Edit: I'm an OSCP now, and you can read my review here, but to briefly answer your question.
OSCP is nothing like C|EH, SSCP or any of the other courses I know that are out there. It is extremely practical and leaves tons of opportunities for further research and development on your own.
If you're looking to learn something new or establish ground in I.T. Security, the PWB course is awesome. It teaches you the ropes, but leaves you to climb them ;D.
Generally a 60 day course period is recommended if you can dedicate 3-4 hours daily, or 30 days if you have prior knowledge or can go 8 hours a day consistently.
Rather than another accolade the course is meant you teach you know to deliver offensive security at a practical level, not only in theory. You take this course and there will be countless times you will be frustrated, bogged down, discouraged, but you have to keep going and as they say "try harder".
The labs are not difficult, they're challenging. But the high you get when you break through the obstacles is worth it and the cost.
If you're doing it as a cert. then it'll be disappointing, if you're doing it to learn, welcome to the lot.
The course doesn't have any major prerequisites as they teach the basics from ground up. This is what I feel you'll need:
- Knowledge about TCP/IP
- Linux Usage & Navigation
- Basic understanding of exploits and payloads in Info. Sec.
- Basic Scripting/Programming Knowledge Helps
- ...and the most important, determination.
Further Research References: