I think the 465's are good for what they are.
Well supported in the aftermarket and still easy to find OEM bits new and used (You will just have to live with the Vacuum formed plastics - and thats that until Concourse gets around to making some awesome repros).
Seat foams/covers and bases, cables and controls, final driveline, filters, fuel tanks, graphics, clutches, electrics, brakes, spokes/rims all available any day though the net or local dealer.
Hop up parts for susp locally available, good interchangeability with YZ and IT models or the era for mechanical parts.
Hold thier value well (not super expensive but you would not have much trouble selling one at respectable market value as they have cult cred - thanks to S. Gall).
I think the best part is that you can still get one at a reasonable price.
Popular at most vintage events for pros and novice alike - what is not to like about these machines?