I got the Domino soon after it came out (wahoo! steel pins!) and am a hobbyist. It is definitely a chunk of change, but it makes fast work out of so many things including so many things that aren't just joints. Admittedly, you could do them other ways more slowly. That's partly why the cost of entry is so high.
If you decide to do the 30-day trial, ignore the included manual and read Rick's supplemental manual. His is a super set of the original (well, my original, dunno if they have updated it). Have a project in mind like a cabinet base with face frame for the shop and do it with the tool to see how you like it.
In my case, I wasn't as lucky as Jerry and mine needed most of the calibrations described in the manual. It makes you understand the tool better, though. Now, if I could figure out the 1mm discrepancy on one side of my outriggers I'd be happy (for now, I do the accounting "minus 1")
One thing that %$@% me off with the Domino in the beginning were mortises that weren't parallel to the fence. They leaned a little. This might have been Peter's issue as well. It also %$@% me off that it wasn't consistent about it. What it turned out to be is that I have to set the fence height and lock it while the 90* fence is upright and locked; otherwise, there's some play and locking the height locks is canted. So, to me, it's procedure: set fence height, tip fence to 90*.
For plywood, I usually Bowclamp ('sup, Craig!) it down to the assembly table then do the mortises.