Abetta's do not hold up. Very uncomfortable to ride in for any length of time.
I used a Big Horn synthetic on my black gelding for thousands of miles. Never a problem with it for him (no white hairs, sore back and even sweat pattern). No sore back or legs for me. The saddle is tinged gray from age and wear.
The saddle fitter/maker that I have out once a year to check fit on our horses said it was the best synthetic saddle he has come across.
I agree they don't hold up but as for comfort?? I don't agree. I find mine comfortable. I do weigh 193 pounds and put about 3000 miles on it before the fender wore out. You can buy replacement fenders from Abetta
As for fit I again agree that mine never fit very well. It bridged, meaning it didn't touch the horse in the center, only the 4 corners.
I posted on this in A Cold Backed horse
Check out this post along with the pictures of the english billeting in post #6
A cold backed horse?