I've recently been jamming with my old band, and I decided to bring my Rick to rehearsal last Saturday. I've never actually taken the Rick out live or mixed it in with a band, so I was curious, since I almost exclusively used my Jazz and Sterling live with this band. Long story short, I was amazed at how well it blended in with our overall sound. I thought the Rick might be too barky or aggressive, but a simple tweak of my tone/pickup setting and I had perfect clarity with a nice defined low end thump unique to Ricks. I had recently installed the capacitor on/off pot in mine, so I ran a pickup blend of both pickups with the cap engaged, and thus got clear crisp top end with a huge low end as well.
I think a lot of people get turned off by Ricks because they instinctively associate them with those clickity clackity, trebly Prog rock tones ala Geddy Lee or Chris Squire. Obviously, McCartney got an entirely different tone from them, but it just goes to show that a Rick can be versatile.
A few gripes/caveats about Rickenbacker the company, however. They're stubborn and arrogant, mistaking archaic outdated technology with charm and idiosyncrasy. The bridge on a Rick is the worst POS I've ever encountered, and you have to remove all the strings AND remove the bridge to intonate the damn thing (Unless, of course, you've got a right angle phillips head screwdriver). Then, of course, you don't know if you're intonated perfectly until you reassemble the bridge and restring it, whereby you have to do it all over again until you happen to hit it.
Rickenbacker knows this and they don't care to do anything about it.