TIEW - I believe that has got more to do with instrument approaches being designed without any thought to airspace classification or traffic separation. That's fine in Class C or D airspace with ATC present, but silly in Class G regardless of the speed differentials. The non-aligned IFR approach for a Cessna 172 may be fine, but high performance aircraft should arguably have separate IFR approaches that keep them above bug-smasher altitudes until aligned with the runway.