I love this. It fixes most of the system. Hey perhaps you cant upgrade some of the best crits, but you will because some system will evolve which will let anyone upgrade crits just for a day or so.
All powertraining is effectively stopped on MP3/4, It means you will be forced up if you want to continue fighting. And the current issue of "overpowered older players" will peter away as those accounts either leave or move up. The problem is currently an issue where older people have crits you shouldnt have, but that will merely mean the younger mp3's will go across the levels, leaving the old "vet mp3's" to sit there, and do nothing.
Its a great change and means that you will move up and not continually train, If you want to fight, you SHOULD be at mp5. Period.