I had the same issue when I was still doing MDI - it was frustrating and infuriating. I examined everything in my routine to see if there was some thing I was doing that was adding weight, and it came back to one thing: the Lantus. Some long lasting insulin’s can cause weight gain, and sure enough every time my dosage was raised I would gain 10 or so pounds. In a matter of a year and a half on it I went from 120 to 160. I’m not sure if you MDI requires a long lasting, but that was the tipping point for getting the pump for me.
Since being on my Ping I’ve lost nearly 25 pounds. The weight loss has been slow - I still have to exercise, eat reasonably, etc - but it is actually happening. As opposed to when I was on the Lantus and it just wouldn’t budge.
(Also, I found that the Ping is much better to deal with in the clubs/bars! I can hide it my bra! It blends in pretty easily if I’m wearing the right bra. No more whipping out an insulin pen or hiding in a bathroom to dose!)