I'm using put.io for about half year, and I love it.

Pros:
- supports IFTTT (yeah you could even make your lightbulbs to blink when a download is finished)
- it also downloads videos from youtube and most of the porn streaming sites like xvideos,
- you can share folders with limited number of friends,
- if another put.io user has downloaded the same file from the same URL that you want, it will not download again, and no seed is needed, it will be just made available to your account instantly. (a 20GB download in ONE second? WHAT?!! )
- accepts bitcoin,
- RSS automations
- there are a lot of APIs and APPS available for it such as:
a dedicated torrent search engine for it which is awesome,
apps for iphone, android, apple TV etc,
ability to mount the seedbox as a hard drive using rclone,
Kodi addon,
channel for Plex,
Siri Shortcuts,
Browser extensions...

Cons:
It's not the cheapest, it starts at 10 USD for 100GB , 20 USD for 1TB , 50 USD for 10TB.
But if you have a huge hard drive and just transfer everything to it anyway, 100GB should be fine (it is for me).