Medtronic 780G vs t slim x2

Hi, what’s your experience comparing these two pumps and in particular about the different sensor (guardian 4 vs dexcom)?

Marco @beppegol, I haven’t used the 780g yet so I can’t provide a direct answer to your question; I have used the t-Slim x2 for 4.5 years and highly enjoy the performance and the results.

As my t-Slim is out-of-warranty I evaluating options foe a new device; currently the 780G is third on my chart. Two reasons pushed it below a new t-Slim and the iLet: First reason is the possibility that the many possible bolus possibilities [basically I like this theory and know it will be good for many] will supercede the small amount of insulin I now need. Second is the Guardian 4 about which I haven’t seen actual user reports - prior Guardian sensors did not have favorable results. And the Guardian 4, although FDA Cleared, has yet to be Approved fir insulin dosing.

Just my CURRENT thoughts.

The data submitted to the FDA so far suggests the Dexcom G6 and G7 might be wrong less of the time than the Medtronic Guardian 3 and 4 if you compared everyone using the 4 sensors. The only data that matters how well the sensor that works with the pump you want works for you. Are you using a CGM now? If so, which one?

The Guardian 4 sensor can be used for automated insulin dosing as part of the 780G pump system. See

I’m also starting to look into new options since my TSlim X2 will be out of warranty this January.

The 780G was referenced by my Medtronic rep 4-years ago when I last had to make this decision. It’s disappointing to see that it took them this long to mend things with the FDA to only recently receive approval and are launching it now. The physical form factor of the pump hasn’t changed since the 630 when it launched in 2016 which to me was a step backwards from the previous Paradigm pumps.

Guardian 4 uses the same 2-piece design from Medtronic’s parts bin initially launched in 2011 that they called Enlite. It’s an awkward application and taping process in my opinion.

After 3.5 years with the Tandem my biggest criticism of it is that the Control IQ algorithm feels too conservative for me, but may be optimal for you and others:

“If glucose values are predicted to be above 180 mg/dL, Control-IQ technology calculates a correction bolus using the Personal Profile settings and a target of 110 mg/dL and delivers 60% of that value. An Automatic Correction Bolus will not occur within 60 minutes of a bolus that has been delivered or cancelled.”

It will “target” 110 mg/dL but only deliver 60% of the needed value to get you there, relying on basal adjustments to get it the rest of the was as needed. It will only increase basal if it predicts glucose >160 mg/dL. For me personally, it has been ineffective for dealing with significant highs. When it delivers correction boluses, I usually receive micro-boluses that range from 0.25 to 1.2 units due to prevailing insulin on-board . It wont really get me to 110 mg/dL due to the conservative algorithm. For that reason I don’t use it unless I am worried about insulin stacking overnight and I do not want the system to try to get me to 110 mg/dL (due to a significant amount of insulin on-board while I’m asleep).

Instead I have “Sleep” mode active 24/7. Sleep mode targets 110 mg/dL but it does so using basal adjustments only; it will deliver the insulin needed to get you there and keep you there within reason I’ve seen basals ramp up from 2.0 units per hour to as high as 12 units per hour to address a trending high; in those situations I’ll issue bolus corrections on my own as needed. With Sleep activity profile enabled I will generally wake up in the morning in that ~110 range. If I turn off the Sleep activity profile I may wake anywhere from 110-170 in the morning because of the conservative guardrails of the base algorithm.

I would be tempted by the 780G if it was more aggressive in treating highs than the current Tandem algorithm, but in my many years of experience with Medtronic sensors, both the Sof-Sensor and the Enlite were full of many promises that were never close to being fulfilled. My last two years on the Medtronic 530G I used the Dexcom G6. Hopefully Guardian 4 is better, but it is still handicapped in my opinion by it’s dated physical form factor which can make it more difficult to apply than necessary, make it susceptible to dislocation, and also catching on clothing.

Medtronic’s answer to the one piece designs of the Dexcom G7 and Libre will be with what they are calling “Simplera” and “Instinct” (the latter one intended to pair to a pump). Since Guardian 4 just recently launched in the USA, it may be awhile before Medtronic is ready to replace it with the next generation sensor form factor.

As a counterpoint to my previous post here are some pretty critical feedback comments from users of the Dexcom G7 at the end of this mostly mostly positive review:

Dexcom G7: A Critical Review & Comparison | Integrated Diabetes Services

I’m using g7 after about 3/4 of a year on g6. I’ve also used the first couple generations of the Medtronic sensors up to enlight.

An option to consider @trifona, is the Beta Bionics iLet iAIDs. This system uses the effective Dexcom G6, at present, and has a software toggle switch - much like the new Tandem software - allowing user to change between the G6, G7, and Libre3 sensors. Right now the iLet is holding the #2 spot on my “next pump list”.


Care to share your thoughts on the G7 vs G6?

Sure thing! @trifona g7 has a 30 minute warmup Time starting from when you open the applicator, a typical warmup is therefore 20-25 minutes. There is no separate transmitter so I put my new one on 30 minutes before I take the old one off and I have zero lapse in readings. Overall the g7 warms up a little closer to the truth, rarely reads low at the beginning unlike g6. I find the signal a little noisier (more weird dips and spikes) than g6. I find the Bluetooth weaker than g6, I used to pick up my sensor with my phone 2 rooms away.

G7 applicator is very much better for me. I hated all that plastic on the g6 applicator and the g6 was more awkward to shoot on the back of my arm.

G7 yells at you that it expired, but keeps sending numbers for another 12 hours after “expiration”. Nice if you are like me.

G7 is way smaller and has less contact with my skin, the overtape that comes with g7 is ridiculous. Still, I get about the same amount of adhesive failures with g7 as g6. I get a little less irritated skin with g7.

G7 app has a silence all function, which is vastly superior than the g6 app. After it wakes me up I don’t need another alarm that I’m low and certainly not for the 25 minutes it takes for CGM to see the rise in bgl. Vast improvement.

Overall accuracy has to go to g7 if you account for first day stuff with g6. After the first day, g6 and g7 are equivalent.

Overall, g7 is better than g6 for me. Slightly better is probably more accurate. Costs less because I don’t need a script for transmitters, and 1-piece is definitely less of a pain in the neck. Good luck :peace_symbol::shamrock:

Thank you for the link. One thing I noticed: as I recall when I started using the G6 the abdomen was the only approved location, but people started wearing it on the arm. If I’m reading chiefly, the G7 is approved for the arm instead. They flipped it. Hopefully that will open up in time.
There are overpatches you can buy for the G7. I like Simpatches - although some people don’t like the size they are available as are similar products by other brands.