I pulled 1 each from 2 Topps Cereal boxes and redeemed them both. I got a 59 Al Smith ($8) and a 66 Bob Locker ($5). Nothing huge, but not bad for free cards. I haven't had them sent, though, so who knows what kind of condition they'll show up in.
From what I've seen, though, it's definitely more misses than hits. It makes sense when you figure how many more cards were produced from the 80s on. I wouldn't pay for any redemption cards, but they're kind of fun if you pull them from a pack.