have anyone ever had any experience or comments (good or bad) regarding to the "R1" height adjustable springs?

what about by putting this spring on a koni yellow on a 5th gen? i'm not going on track or any racing at all. just regular street use with a better "look".

 

I've never heard of R1s (not a good sign). I suggest skipping the adjustables and going with lowering springs. Coilover sleeves (the springs with the adjusting sleeve) can give a harsh ride, rattle, squeak, etc., and there's a possibility of the spring coming off it's perches. Also in order to make the sleeve fit tightly to the shock they sometimes come with spacers to put in between the sleeve and the shock. This spacer becomes a weak link in the suspension.
If you're not racing then you don't really need adjustability. Eibach Pro-kits or H&R Sports are good lowering springs that still provide a decent ride.