MS Forecaster: What are the limitations

Jim McCloskey's Profile

I have a new client who uses Great Plains but does their modeling using excel (25 sheets).  This is a 30 store grocery chain doing $400 miilion.  They have purchased Forecaster but never implemented. 

1.  Should the client implement Forcaster or eat the cost and choose a better solution (?)
2.  If we choose Forecaster, where can I find the best training for the client?
3.  Since they use GP and Excel, how long should building an improved model using Forcaster take?  a week?  2 weeks?