They are great. From Sweden and they are bunch of hackers. They helped pay for mullvad and working on their own clients. They were very early with supporting Wiregurad.
They also over tons of payment methods, including the ability to send them cash threw the post office.
I don't know if they're reputable, but I have used them in the past – mostly because they supported wireguard pretty early on.
I had no problems with bandwidth or connecting.
PIA (Private Internet Access) is sponsoring Wireguard development: https://www.privateinternetaccess.com/blog/2018/09/the-curre...
It depends on if you have AES-NI (for AES) and PCLMULQDQ (for GCM), or similar features on non-x86 architectures. Without them, AES-GCM is usually much slower than Chacha-Poly.