When I did my IMC rating a few years ago I invested in Flight Sim 2000 and passed in the minimum 15 hours. I did also have a yoke, rudder pedals and 20" screen as you need to have a degree of realism. PC based flight sims are good training tools for instrument flying only and really only if you have the hardware to go with it (yoke, pedals etc.) I undoubtedly recouped the cost of that through reduced training hours and being able to learn at an unhurried, unpressurized pace in the comfort of my home for as long as I wanted. I still regularly practice let-downs, SID's STAR's and any other aspect of instrument flying. Go for it dude.