I've had a Teeter 16 inch for a couple years. About as well-made as any of the premium Dobs. Well-engineered with features like diagonal heater and large fans installed and wired-in. Wood work and finish are very nice -- not quite fine furniture quality, but very pleasing nonetheless. Scope frame (upper tube, truss assembly, mirror box) are well-designed and very rigid -- more so that some other makers.
The scope arrived in relatively good collimation. I've seen some other makers where proper collimation was somewhere outside the available adjustment range -- requiring some mods to fix. Rob seems to have paid attention to proper optical alignment.
Mine did have a couple "warts" like it would not quite reach the horizon -- elevation bearing placement was a little off. On the other hand, I almost never observe that low.
Also primary mirror cell was a little loose -- did not have a positive lock-down like some others -- Rob's cell bolted-in from the sides rather than from the bottom.
Rob used a tilt-out mirror cell on mine -- you tilt out the rear cell and pull out the mirror for transport. Some scopes I've used were designed so that the mirror+cell were removable, and I think I like that design a little better -- less chance of touching the mirror front surface. But its a relatively minor point.
Virtually all premium Dobs I've used had some sort of minor issues as delivered from the factory. Or needed some sort of mods, like adding fans to the mirror box, wiring, etc. Or needed mods to the truss structure to make it more rigid. In this respect Rob's scope was very solidly engineered and relatively "complete" as delivered.
I can't really comment on Rob's optics, as I had already bought the optics before I approached Rob about building the scope. But his mirror providers do have good reputations.