Well, the last OTR shows left the air sometime before my 2nd birthday so I don't recall them, but I listened to "Zero Hour" and the "Mystery Theater" in the 70s, and later discovered the older stuff.
Anyway, a few more quibbles with the S/XM Radio Classics channel. The shows seem to be butchered a bit more than usual, probably so they can squeeze in more Radio Spirits/Music Rewind spots. (I especially loathe it when they cut from "Broadway's My Beat" the closing soliloquies offered by Danny Clover. Those musings of a Broadway now long gone have a certain poetry to them and for me they make the show.)
Also, especially now that Radio Spirits is supplying the shows, they could have better source material. I realize that pristine discs and tapes are either hard to come by, gathering dust in a network or sponsor archive, or hoarded by collectors. But many of the shows I hear sound like they come from old "Aston's Adventures" 4-track 3-3/4 ips tapes, with a horrendous amount of print-through and crosstalk, along with third- or fourth-generation dubs. But, as someone else stated, we're lucky to have the shows at all.