Well, I was pessimistic. Just pushed an update that slightly more than doubles the execution speed with a PR to the main depot pending. It is very close to 20 times faster than the original.
Though it'll still be kinda slow on a Model I, I've written an about 9 times faster Z-80 code for the network evaluation. I imagine the pull request will end up in the main depot but for now you can find it in https://github.com/gp48k/z80ai
I think I can do a little bit better; maybe 10% faster.
It is in the sense that Radio Shack put TRS-80 as a brand on all of their computers up until the mid eighties when they started to move into PC clones. Xroar emulates the Color Computer which was known as the "TRS-80 Color Computer".
Though, to be sure, most often TRS-80 is used to refer to the Model 1, 3, 4 line. But plenty of people will think of the Color Computer when they hear TRS-80. Or, possibly, their line of rebranded pocket and laptop computers like the TRS-80 Model 100 or TRS-80 Pocket Computer 1.
The version for the Model 3 runs on stock hardware as it shipped in 1980. It has a interrupt that fires every second vblank. Thus it is possible to get in sync with the beam but to remain in sync the program must keep track of every cycle it executes.
The Model 1 version does require a hardware mod to get access to vsync.
I wrote those programs and couldn't have done it without something of a virtuous circle of trying stuff on the real hardware and then improving the emulator to more accurately model the hardware and so on.
It really was a term of derision. Sure, some may have used it affectionately and even more might do so now, but by and large it wasn't used in kindness.
To cite a reference, the first issue of "80 Microcomputing", a magazine dedicated to the TRS-80 line of computers. See the second paragraph of Wayne Green's editorial "80 Remarks" on page 8: