Great for you Mary. I don’t. just goes to show we’re not all the same and don’t all have the same experience or indeed needs from our tyres. is that 4000 miles between 3 bikes ie. 3 pairs of tyres? or did you mean your GP4S have done 4000? That’s about what I’d expect the tread to last, but a tyre that starts to fall apart well before the tread is worn out is of no use to me.
Rascal, If you found Gatorskins great. Pretty much any race tyre will perform better in every way (other than puncture/cut resistance). Will you notice the improvement? Who knows?
You haven’t given any indication of where you intend riding, what quality of roads, in what conditions or what qualities you even want from a tyre.
stating your weight, preferred tyre width/pressures and how you ride would be even more helpful.
By all means buy the GP4000s (that is a very good price). I’d be making sure I kept my receipt that’s all.