I disagree, I think that since it keeps the same alt mode and 'feel' of the character intact in all the toys, it makes it for a great reference on how toy evolution has progressed.
From a little green block guy with tiny arms to a fully articulated transforming robot and when it comes to the BT, a great realistic scale model.
Joe Average will be able to notice the design progression more if he sees consistency in 'each step of the evolutionary ladder'.
If we show him stuff like G1 Onslaught next to Universe Ultra Onslaught, Joe Average will just seem them as two different toys not a progression of the same character or design engineering due to the considerably different robot and and alt modes. The same goes for Powerglide, particularly if the Universe (gray) version is used.