There have been no major updates to Voice in a while (thankfully), but lots of marketing and buzz around Project Fi. I can't help but think that Google will kill Google Voice in the future. Google Voice is integrated with Hangouts as well, which means one of those features will go away, assuming the OP is true. I love using Voice for the same reasons you listed out, but I dread when Google decide to make a change in this space, I'll be very disappointed.