I'm only 3 days into ownership, I have 2014 Rs 6spd. The car is a blast to drive, and I have driven a lot of the cars in this bracket. I was driving a 2007 nissan versa HB, and the ONLY thing I miss about that car were the seats. The RS seats are very pretty and all, however I feel they lack bolster. You kind of sit on them, rather than in them if that makes sense? So aggressive cornering gets a little scary at times, I actually try to keep the arm rest down to act as something to keep me in place when cornering hard. I'd still imagine their better than the other sonic seats though. The steering wheel in the RS is very nice, so that is a plus over the others. The rear disc which is only on the RS out of the hatchbacks is a huge brake improvement. Actually almost put myself through the windshield the brakes were so strong and i wasnt used to them coming from the versa which had rear drums. The close gear ratio 6spd which is only on the RS adds a nice peppy feel. Though you do give up a few mpg's having it, but nothing substantial. With a heavy foot, and doing a lot of stop and go driving the car tells me im averaging about 27mpg's. I am no where near shifting where i should to be able to save gas. Straight highway cruising though, im easily in mid 30s which is great for me.
And last but not least the RS package just looks plain badass compared to the other sonics. I think the topaz blue that I have is beautiful, but the gray is really nice imo as well.