Roux actually makes for a better sense of things like FMC and blockbuilding, things a lot of CFOP-ers dont know as well. I think rouxers actually have a better understanding of the cube.
I use roux-n-skrew for square-1, meyer for bigcubes, and CLL for 2x2.
In reality, roux is the reason in sub-5 with 2x2, because I just recycled all my CMLL's and used them for 2x2. so roux can get you places, even if you dont think it can.
Think about it this way: 99% of the cubing population use CFOP. if 1% use something else and the top 10 are randomly selected from those 100, what is the chance that a cuber will solve with a different method? not too high.