I've been using the 120v OTR since September. As a microwave, I love it! We previously had a Sharp Half Pint cube that was 18 years old, so anything was better, but still it's really great in that capacity.
With the 120v, I've noticed the Speedcook is not that much more speedy than using the oven in my range. I have heard wonderful things about the 240v, both as an OTR and as a wall oven. It really is very speedy, and food comes out of it beautifully. I do like the quality of the food that comes out of the 120v.
One regret I have with mine: I did not realize that with the 120v OTR you cannot fit a 13 x 9 casserole because the turntable must turn at all times. My mother's GE OTR has a rack you can attach so you can bake large casserole dishes on the convection setting. I shoulda been a bit more careful about checking which OTR did what