For Nathon East:

The bottom line for selecting an IFR trainer is usually economics.  An IFR Cessna-172 rents for about $ 80/hr plus instructor.  A IV-P costs approx $ 225/hr just to fly plus instructor.  The approaches "can be" flown at just about the same speeds.  Yes, there would be advantages in using a IV-P as a trainer but certainly it would not be a very cost effective decision.

Happy Training - Bill Hogarty