I can say this.
I wasn't a huge fan of SF4 when it first came out. I thought it was ugly and stupid. It ended up becoming one of my favorite fighting games the more I got into it.
When it comes to SFV, it looked way better than SF4 at first glance, and was easier to get into. Outside of that, I found myself not being as interested in watching it like I was when it comes to SF4. It just felt like something was missing.
Eventually I got more and more into the game and learned to take the bad with the good. Ranking up in the game was a lot of fun. The LP grind in ranked can make a nikka feel
or
SFV had a terrible start and slowly dug its way out of the hole. I'm glad Capcom were able to turn things around.
Hopefully with SF6, we won't have to worry about Capcom trying to redeem themselves. I'm confident that launch will be much better this time around.