The first microcomputer I used was an Apple II, at my school in 1981. This was certainly a lot better than the Timex Sinclairs that appeared in the lab a year later, but I felt, for no good reason other than loyalty to what I’d first used, that the Apple II was also far better than the TRS-80. (I didn’t know about the PET at the time, but I surely would have felt the same.)
But I’ve just had a careful think about this, admittedly in light of what I know now, and surprisingly, at least to me, the TRS-80 came out far ahead.
The Apple II would certainly was attractive for having colour and high-res graphics, and it also was by far the easiest to get started programming in assembly. Not only did it have the best low-level documentation and a built-in machine-language monitor, but it even came with a built-in, albeit simple, assembler!
But if I were sent back in time, or at least knew some of what I know now, there are a host of reasons why the TRS-80 wins.