I agree that the Domino can be a very useful machine, I use both the 500 and 700 in my workshop and I wouldn't be without either of them.
But a lot of the Domino lust that I sense on this forum isn't entirely justified. Because the Domino has some important limitations that don't get the publicity they deserve, and there are plenty of alternative methods of getting the same job done. After all lots of amazing furniture was being produced before the Domino was even a twinkle in Festool's eye!
The Domino gives you a decent amount of flexibility around the depth of the mortice, a bit less flexibility around the width of the mortice, but the thickness of the tenon is very, very limited. Consequently to get the best out of the Domino you need to design your furniture around the restrictions of the machine. That's something I really dislike, both for the limitations it places on my designs, but also because it ends up with everyone's furniture looking a bit "samey".
Before the Domino we would often use a router to cut a loose tenons, most craftsmen over a certain age will fondly remember the ingenious jigs we all constructed for the purpose! And I still regularly use a router for the same job today, taking advantage of the huge variety of cutters that are available and the inherently handier nature of a router. For the really complex, compound angled loose tenons, or those cut in curved components (and most jointed chairs for example will usually feature joinery like this) a Domino rarely provides the flexibility required, but it's often the humble dowel that comes to the rescue. Likewise, for many mitres I'd rather use a biscuit than a Domino, as the rugby ball shape often gets support further out to the very edges, preventing the joint opening up in future years.
I'm not having a go at the Domino, as I said I use two of them, just pointing out that it's far from a silver bullet solution for all your joinery needs. Consequently the hobbyist, especially one with limitations on space or budget, should look beyond the hype before deciding if it's a tool they should invest in.