My experience, different tapes sound differently on the decks. It's not necessary that one deck will always sound better. At least My favourite tapes, I try them on all of them, and stick to the ones that sound the best
otherwise I know the sound of each.
For example, My technics M01 sounds dull, but its transport is bullet proof, and is running a generic head unlike the other two, so its the workhorse for everyday listening.
My Akai CS F9 has great highs and lows, but a bit clinical in the mids, so it gets used for pop, more recent recordings, and the good stuff
The Sony U2 Has a warm and very full mid range, so it gets used for all the older recordings and it CRO2 tapes sound the best on it.
The TC FX170 sounds like crap, so it's used mostly for fast forward and rewind duties for my other decks which have dead/dying rewind idlers, and when i get to need fungus off the tapes
The Sansui D90 is pretty similar to the Sony TC-U2 in character, but has a better transport, and also has a generic head, so gets most of the older tapes for everyday use
The TC 136SD is like the CS-F9, but with a bit more warmth, so gets used for good quality Older recordings.
Get to know the character of these decks, and you'll know which deck suits which cassette