I have a Domino...I cant begin to calculate how much time I've saved not having to do traditional M&T. First project was a couple of outdoor planters. I thought, it will be interesting to see how it fares in a full on watery outdoors situation with soil and rain etc. Two years on and my rails and styles are as good as the day they were smeared in cascamite.
Also last xmas I built a large guinea pig enclosure for my kids and domino'd all the panels, each of which had Perspex routed into a groove. I assumed we'd put the animals in an outdoor cage in the summer so I didn't glue in the domino's so I could dis-assemble it. We're now approaching a year later and its still only held together by the friction fit of the domino's...and its just fine.
I appreciate its nowt but an oscillating router on its side but those Jerry's have really thought it through. The precision you can get referencing off either the base or the fence is superb. It's an exceptional tool. I haven't used my dedicated mortiser since I bought it!