CyberSpace is very compatible to SM2, but the rule set is a little less complex. It is a different setting, and I'd say CyberSpace has more of a Cyber Punk or Blade Runner feel to it.
I've never actually played CyberSpace but I've had the core book for years and used it to complement my SM2 game. If the SM2 rules are hard to understand or not present I normally checked for a different interpretation in CyberSpace. I also used the cyber ware in CyberPunk for my SM2 game, since SM2 did not get cyber ware until Companion 2.
I have not played SM:P but I have many of the books. The games are quite compatible, but as Marc says they can be compared to different versions of RM. A major difference is how you buy skills. Most of the mechanics related to combat and mauvers are the same, so you could easily throw a SM2 character into a SM:P game (but level gain will be a bit odd due to the skill buying mentioned). Many of the rules are identical, and several things from SM2 has been brought straight into SM:P.
I know you say you're going for SM:P, but I'll just have to make a quick advertisementof my
SM2 character generator anyway
.
-Terry