I rode a bike with rival when I was test riding stuff, and I liked it a lot. The shimano shifted a bit smoother, and it was quieter, but neither of those are really important, especially the noise. I have seen where some people complain that the SRAM is too loud, which seems pretty stupid. Why does it matter if it's loud, as long as it gets the job done. For the value, it's a great deal, and I don't think you can really go wrong. If you are looking at bikes, ride some with both groups and see which you prefer. Both brands make top notch stuff.