I have a earlier gen 18i8 that I use on a MacBook Pro and a iPad, and it has worked very well on both, i've never had any driver issues with them. I used it for a bit on a Windows 10 box and do remember having driver issues, but this was 4-5 years ago.
I have a much older Pro40 which I also use with a MBP, and its connected via 3 adapters - USB-C --> thunderbolt 3, thunderbolt 3 --> TB2, TB2 --> firewire 800, and a firewire 800 --> firewire 400 cable. Surprisingly this is very stable, i plug/unplug all the time, and maybe have to do a power cycle on the unit once a month.
the headphone amp on either unit is not great, but the AD and DA is decent (not great), but for $300 you get 8 AD and 4 DA. If you want better convertors get a Universal Audio or Apogee or Prism (something that doens't cost $25/convertor).
If you have a Mac or iOS don't worry about driver issues...