The reviews I'd like to see about TC / piCore would come from such legendaries like Doug McIlroy, Brian Kernighan, Rob Pike and nearly all the members of the TUHS mailing list and early crew of Unix.
I have a feeling they would approve wholeheartedly with TC, not just for size, but for not just doing the same 'ol thing, but maximizing resources, yet still be as meager or as bloated as you want.
TinyCore Linux really does solve Rob Pike's "What's wrong with Unix" question posed decades ago.
I don't know how large the TC dev team is, but ATT stuffed 15 guys or so in the terminal room in the attic, and magic happened. That and of course the Berkeley and other Uni's contributions. I believe the same magic is going on here, and is why I'm slowly converting my hardware to it, despite all the other pretty choices out there.