I have the minimed CGM and while it's been helpful here and there, it's also been very expensive. I haven't used it since June (now 26 weeks). It was helpful to see trends, but in some ways it also stressed me out more to wear it because I programmed in the pregnancy guideline numbers - maybe should have given myself a wee bit more leeway. I've been swinging around a lot with my numbers so I may try it again in the next week. I have 2 sensors left and I'd rather not buy more if I can help it (for a box of 5 I think it was $200 Canadian).
It usually read a little lower than I actually was (within 2mmol usually). I had issues with lost connections at night when I put my pump under my pillow - even though it was within 2 feet of the sensor. If I attached it to my PJ bottoms it was better but annoying. I was never able to wear the sof-sensors because they were too painful but the newer Enlite's were fantastic - easy to insert and I could wear them for 6 days no problem. The difference between the wire of each of them is huge (enlite is like a piece of tinsel, sof-sensor is like a catheter).
I've heard the dexcom is more accurate and most people prefer it. If I had the money I would shell out for the next time I'm pregnant.