I have just completed my CPL/ME/IR and can highly recommend doing IMC during hours building. It certainly helped me with my IR. With regard to the hours reduction, not sure on that one, but I think doing an IR in 50 hours will be challenging enough for most. Speedbird, where are you flying from at the moment? I see you are from Manchester and can highly recommend an IMC course by Martin Rushbrooke @ Barton. The thing is there are IMC's and there are good IMC's and you wont get more professional than Martin.
PM if you need to know more.