Well, it's not the cheapest way to get a new computer running Amiga OS, but on the other hand, it does go very fast with a dirty great PCI-e port to delight any one of selection of fine graphics cards.
I guess at the other end of the scale, you have things like Pi emulators, which can let you play Amiga games pretty well. They won't do as well as Steam boxes, which I guess might be one of the Tabor's selling points?
It's not like the architecture is that different, Arm Cortext 7 against Tabor isn't so different, but faster memory, better connectivity, 3d hardware graphic rendering, etc.
I guess if you got a souped up Pi variant to run an emulator on, like a Beagle bone, you'd get faster Amiga emulation too - but how fast do you really need? How much do you want to pay to run Amiga software? Cortex Arm 8 is expensive, but has a huge host of hardware options (and licenses to pay for).