those magazine reviews are not much to go on these days, with the usual of todays mods all of the 1984 Japanese 250's would make about the same power and handle about the same too. like regardless how bad a the CR's rear shock was/is, any number of rebuild or replacment options are an easy fix, the waterpump housing is a different story though. same goes for the YZ L's Zspokes and front forks that didn't work (if you believe the 1985 magazines), once again a simple re-valve and some later rims will solve any issues. a 1984 RM may have been slow in 1984, but who's going to run a stock engine-pipe-carb option these days anyway?
also i'm sure all are aware of the 'Wiesel' factor whenever a bike is being tested