Although they would be considered 'old' technology, IMO, they are still one of the best rifle for FT.
The action itself is perfectly ambidextrous - only the stock makes the gun 'handed'. Direct pellet feed into barrel so you can feel the fit of the pellet, no transfer port cut through the barrel into the bore. Easy to verify loaded or clear status. Extremely good trigger mechanism and with a Mk3 regulator, very reliable and extremely easy to service when required. Barrel fully floating so reservoir tube doesn't need to be torqued on stupid tight to prevent any POI shift.
The only weakness of the design that I can think of is the little slot for the striker cocking lever can allow moisture to enter, although to be fair, when I used mine on a wet day I bagged between lanes and when I got home found very little had gotten into the action.
All in all I think there was a lot of features gotten right on the Pro-Target and the 'improvements' on its replacements are retrograde steps.