proflex differences

Looking for some info on proflex differences, between 1995 and 1997. The earlier ones used the gls linkage and the later ones used the pro active swingarm. Is there a difference between them and is it just a marketing term for single pivot or even URT. As would like to get another proflex, ideally a 1997 beast with the pro active. Had one, sold it.

Having owned several Flex's that have had the pivot forward of the Crank/BB and seat post and where the later ones sit rearwards of the Crank/BB. As to the benefits i'm not sure and in all honesty both set-ups have slightly different riding characteristics but as to pros and cons over either design i could really comment as i enjoyed riding both. I also own an Orange X1 and it does have a URT (Unified rear Triangle) where the Crank is fixed within the URT and the whole unit pivots independantly. Again the X1 rides different to the Flex's, the X1 doesnt bounce as much as the Flex's and when applying drive rear wheel traction seems improved. One of the most significant differences i have seen is with the removal of Elastomers and fitment of Noleen or Risse shock units, once set up the ride of a Proflex is improved greatly.

Good luck with the search for your next Flex