Thank you for your reponses.
I actually do very much enjoy my sim sessions as they are a fantastic learning tool and if performed correctly (as they are by the majority of instructors from my years of experience) are very useful.
The question above related to a collegue who just returned from "the most harrowing sim session he has ever encountered". The pressure was incredible and the unrelenting nature of the instructor coupled with a very inexperienced F/O seemed to be a tad unrealistic!
WWW, I take your point that it gives you exposure to non normal situations,and this in essence is as I say, a fantastic learning period. However when the scenarios form part of a LPC/OPC, (which MUST BE PASSED) they place pilots in a precarious position. I think the instructor should be able demonstrate the sucessful resolution if the incumbant makes a mess of it.
Once again, thanks for the inputs.