I just joined for a month, my subscription just ran out.
All old clips are there still, but there is a limit to how many you can download in your subscription. I think the limit was 45, so it's fairly decent. You can still see the previews to see if you like the clip. And you get to choose what resolution to download at. You "unlock" the clip before you download it, and once unlocked on your account, you can download it as many times as you like.
I found the clips to be of overall high quality, the newer clips generally more interesting to watch than the older ones, so there is improvement. The models are great and I was very happy with most the clips I got. Ended up not downloading all 45, as I was a member previously before they added that limit.