I would like to join this conversation... I play mainly bass but for homerecording purposes I still have guitar. So I look for gear that would fit both.
I recently tried couple Delays:
Boss DD-3 (MIJ), DD-7, RE-20,
EHX Memory Boy (regular version),
Line 6 DL 4
and I also have one very vintage Polish guy called Kotwicki built digital rack unit.
My impressions:
1) EHX Memory Boy - when I was doing research online I fall in love with analogue sound of delays. When you listen to our band, Tale of Diffusion, the piece called "Melody Man", at the end there is great solo of our guitarist recorded on high overdrive & our vintage polish delay that we were modulating the time of delay with knob while he was recording. I wanted to had that option in my pedal so I was looking for something you can use expression pedal instead of hand.
Memory boy has great modulations, expression pedal option, so I went for it.
Unfortunatelly it did not sound that good with bass that I expected & with longer delay times it was getting little bit distorted feedback sound which really annoyed me.
Also the expresion pedal trick was not working as I expected. Finally I was looking for longer times than Memory Boy had...
I end up selling it.
2) DD-3 - first delay pedal I tried with Bass. I loved it. It is very good sounding pedal for both guitar & bass. It has some decent delay time to, so you can get to longer delays & short ones too. No feedback distortion. Very rythmic.
The things that was missing was not the sound but the options: tap tempo & expression pedal.
So I got DD-7
3) DD-7 combined the anologue sound (in analogue mode) with little of modulations & digital clean repeats. Also had expresion pedal option, hold mode, tap tempo. All I needed. Sounded great. But...
4) When you start checking pedals you always come to conclusion you want more options, more modes, better quality... So I end up thinking it would be nice to have more options using more presets in delays. So I bought Line 6 DL4. Which in fact won my heart among others. It sounds great (bass & guitar), have all options I wanted & can store more presets & record 14 sec loop.
Disclaimer: still the expression pedal use for adjusting delay time on the go is tricky part of my experiences. Polish digital delay that hushes, hums and makes all the unnecessary noises works best...