I also went from 105 to Rival, and I'm happy with the change. I don't often shift chain rings, because I tend to have knee problems with the big chain ring. I did have shifting problems when I was playing around with the big chain ring a couple of months ago, but that was because it needed an adjustment. Since then it's okay.

My current handlebars are smaller than the old ones (WSD vs not), and I think that makes it a bit easier for me to shift and brake now vs. before.

But yeah, you should do a test ride to see for yourself.