I switched to Tandem after 12 years of Medtronic pumping.
I like the tslim. The only drawback is that I can no longer use Apidra insulin. Humalog and Novolog work fine but Apidra is slightly more viscous and incompatible with the tslim.
TSlim is very easy to learn/use and dare I say more stylish to wear! I still use the Medtronic pump clip which I keep in place with Velcro on back of pump. Tslim clip is a bit klutzy.