I recently bought some original rockets and decided to run a comparison between them and the r2'si on my 'dune ported' stock stroke bike. Milled stock head, 28pwks, etc. No jetting changes
Fitment and Design- Fitment of R2 pipes beats the rockets hands down. They clear the petcock unlike the rockets, are clear of your legs and line up to the mounts so much better. R2's have orings to seal the stingers while the rockets have the silicone couplers, probably personal preference here. Both would clear the air filters decent. Rockets have stainless stingers and a nice silencer design which is skinnier but longer than the r2's. The stingers also mount to the silencer can with bolts as opposed to the cheap rivets which need replaced on the r2 silencers after your first few rides. Stinger size is smaller at .835 on the rockets vs. 1.00 on the r2's.
Power and Sound- They both come on about the same time but the rockets come on alot smoother and seem to have a "flatter" midrange, while the r2's come on hard. The both rev out roughly the same but the r2's seem to hold their power a bit longer while doing so. The rockets are alot quieter than the r2's and have alot different sound than the 'pop' of the r2's.
I do have some helmet cam video i need to edit from this when i get the time. I would like to spend a bit more time with the rockets to get a feel for them to say for sure but based on what i found out here, i wouldnt go out of my way to find some rockets with the r2's available.