I use the website mostly. I can't say I really like the UI, but everything is there and findable (though not always quickly). It is no worse than most other forums. I've been using it long enough that I rarely have to think about how to use it. It makes things a bit quicker when I need to do some research and/or juggle notes before/during/after posting.
I could use the iPad for this (and sometimes do, especially when mobile), but I live in a travel trailer. Walking 15' to a 27" iMac is usually worth the effort. Besides, I only have one comfortable chair, so if I'm sitting it's usually in front of the computer.
Understand, this is not a criticism of the Admins or owners of the forum. It just seems that forums and their software have not been under much pressure to create obvious and/or easily discoverable UIs; not to the extent of tablet apps, where the UI has become all important, almost more so than features.