If the delay time or feedback on the delay is short enough, the precision on the tap tempo isn't vital, but it can still add some meat to the channel. If the delay time is much shorter than an 8th note, and the feedback is a little longer, the delay has a reverb like effect, but is still distinctly different from reverb.
I made a little one take recording a long while back where I thought the drum machine and the delay time on my multi were synced in some way. It played itself out OK, but when I listened to it later it was apparent that the delay and drum machine weren't synced. It sounded OK. Pretty good actually where my playing didn't screw it up. Sometimes not being synced sounds plain bad, but not always.
For longer delay times, I'm giving a big +1 to Wes.
Reverb on vocals is still pretty awesome though. It's a pretty good fallback.
Here's that recording:
SoundClick artist: Mess With Texas - A couple of basses, a drum machine, a mic and a bunch of effects. What more could you ask for?
The bad delay is on the bass and pitch shifted bass signal. It's not awful, but not dead on either. The vocals were all added after the fact. It was just a thing I did experimenting with some effects and the little recording equipment I had, so take it for what it's worth

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