We have been a grasshopper user for a long time. I've found it to be a mediocre product with limited options and a confusing interface. We've stuck with simply because phone calls are not a big part of our business and it is a pain to switch.
Plus, we did the professional voice menu crap, and there is no way to port that over to another system. Shitty phone menus is a turn off to me, so why would I subject my customers to that.