I have a slightly different view, but to Stephen's #3. the dongle??? What dongle? The UAD hardware is the dongle
Okay, my 2 cents(and please take it that way). The plugins sound great, and in some cases, are probably the best sounding, BUT(this is where it goes a bit off the rails) what are your needs? If you want to track with UA plugins, then get an Apollo interface and go for it. Or, if you don't do tracking(and don't care about latency), then use UA plugins all you like(because they do sound great). If however, you wish to track
with the plugins, but don't want to use Apollo, you're SOL because every single UA plugin reports over 1100 samples of latency, which makes it impossible to track with, on any other interface. I run a UA Quad card in my HDN rig, and find myself not getting my money's worth, and if I had it to do all over again, I would have either gone with Apollo interfaces(at the time, Thunderbolt on PC wasn't possible), or I would have skipped UA completely. As great as the plugins are, I can mix just fine with other brands