Considering a new insulin pump have and am looking for advice.

I currently have a medtronic (540? 630?) paradigm insulin pump that is getting on 5 years old. It is showing signs of wear, cracked corners, short battery life etc. So I am looking at new pumps, and was looking for any recommendations. I currently do not use a CGM.

The two options I am considering are 1) the T-slim. I like the touch screen, and just the simple usability features like a calculator for carbs. I also have only ever heard good things about the Dexcom sensor. The problem is I have UHC insurance, and thus the T-slim is not covered and only electronic pumps are. My wife and I both work, and have access to health plans, so I can wait to change insurance, but it will mean waiting until 2019 enrollment.

2) Just get the medtronic pump (670). I can order it basically ASAP, and it will be cheap with my current UHC plan. The reservations that I have are that it is bigger, I still have doubts about medtronic's CGM (I tried their 1st offering about 5 years ago and it was extremely uncomfortable, and had extremely poor accuracy. I was calibrating like 4 times a day beyond normal meal times). I understand they have improved it, but it still seems bulkier than the Dexcom. Also being told I can't have the T-slim really makes me want it more (which I'm not sure is rationale). Medtronic pump also currently has closed loop control, although I heard T-slim is working on FDA approval and may get it as early as next year.

Was looking to hear stories/experiences with the new 670 pump and or the T-slim, as well as any CGM experiences.