I use the 595RS every now and then for the street but mainly for the track, there are also a LOT of members using the RS for hillclimb and track events in the ACT forum, you should ask around in there.
Basically the 595 is a street tyre and not really meant for track use, however it will give you a bit of fun for a while, just dont expect to put down your best times.
595's are excellent for drift though, we have had multiple drifters tell us that they are one of the best tyres to drift on.
595RS is 2 steps up from the 595 in regards to track use, the RS has a much softer tread compound and has a much stiffer tread face due to a "low void ratio", this makes for a better footprint on the road while under hard braking, cornering, acceleration.
The RS is much much better for dry traction than the 595 but is a bit of a compromise in the wet (as any semi-slick is), if youre planning on using the RS as a street tyre you probably wont get the most out of them though (even though they have heaps of grip) as they work the best when they're hot (about 60 - 70 degrees).
Have a look at - www.federaltyres.com.au, www.federaltire.com.tw or www.federaltire.com for more info.
I hope that helps