Less than top line reel-to-reel worth it?

If you are only going for playback you will likely find the rather limited catalogue of commercial tapes recorded at 7.5ips or 3.75ips. Yes, Tape Project tapes are at 15ips but they are expensive.

3.75ips as said for recording is pretty good for the most part. Vinyl recorded at 3.75ips makes for long playback times and still quite high fidelity. IMO 3.75ips is best for FM radio recording.

7.5ips is true high end fidelity on a good reel to reel and will make great playback and esp great recordings of vinyl or cd.

If you are only planning to play back though you will find as I said a very limited library of tapes and a lot of used ones are in mediocre condition due to age, use and possible previous abuse.

i have several reel to reels myself and i love to listen to tapes and make new dubs from vinyl that i can borrow from friends. however, one issue that is unfortunately lacking in the development of consumer decks is that there never was a higher grade of electronics incorporated into these machines before they
fell out of production. unless you have lots of room for a studio-quality transport and custom recording preamps and playback amps, you're not going to realize the full potential of this wonderful format. United Audio's TASCAM BR-20 is something that should have been developed (in some form) years ago, but even if you supply your own machine ($500) and dispense with all of the cosmetic upgrades, it's still almost $20K. surely someone could come up with a more reasonably priced "compact" machine.
Years ago i was away at college and i walked into a little audio shop with a Revox A77 deck playing Dire Straits "Sultans of Swing" through a good pair of speakers. If only i could've laid my hands on $500! the sound just blew me away. you just never forget how good classic audio used to lift you up.

'tactile ritual' beats computer selection.

.
I had a lowly Dokorder reel-to-reel machine back in the mid-'70's and I thought it was the Holy Grail of audio...played through my Sansui 771 reciever. I've never heard a pre-recorded open reel tape. The only recordings I've ever heard on a reel-to-reel machine has been recordings made from LP's. And to me they sounded at least as good as the LP, if not better.
.

Just a word of caution - not sure what the shelf life of a reel of tape is; but older tapes will dry out over time and gum up the player's heads. A lot of used tapes (and even NOS) sold over the internet have seen better days!