I've used rapidseedbox for a while now, my experience has overall been pretty good. I had the 1TB plan for around 8 or 9 usd a month, then I switched to annual to get a deal and recently I upgraded to 2TB. They give you 3 torrent applications on those cheap plans, I use rutorrent after testing all 3 and that works fine for me. I use filezilla to get the files to my PC after.

I had one issue where those downloads to my PC got slow for a while, kind of randomly. I chatted their support (it's one of those chat bubbles at the bottom of their page when you're logged in). They had me switch from either sFTP to FTPs or the other way around (can't remember) and then it was back to normal.

Early on, I had gotten a torrent for a very popular Linux iso that just dropped from a public site, so I accidentally let it seed many, many times over. I want to say that months upload was something like >10tb, at that point the website does complain. It's been a while so I don't remember the exact message but I set up a rule to stop after something like 8x upload and now it's fine.

Overall, decent service for me, relatively fast and cheap, the support was good the two times I used it (though a little slow, but you don't have to stay on the website waiting, it emails you when they respond).

Edit: there are 4, not 3.

I used it for a bit in the past and I didn’t have any complaints with it. It worked well and it’s affordable

From your post if you just want to permaseed either one from the recs is probably fine.

I've used rapidseedbox and ultra.cc in the past, (one months each) and that's just because my server at home is down in the meantime.

Idk how much automation you need and what can they provide though since I just manually load them when I use it.

My recollection of rapid is nice, they have pre-installed tools like SFTP and your choice of torrent client.