I am all for 3D planes as trainers but there are some negative things to look at as well. 3D planes are built super light and cant take the abuse that the "tank style" trainers can.

As far as trainers not being able to get as slow then your not flying the right trainer. A Sig Senior can go in REVERSE in a 10mph wind and be landed in less than 10ft of runway in the hands of a decent pilot.

*just for the record I hate flying trainers and wouldnt trade my 35% for a trailer full of trainers.