The only area with the DD500 that I'm not totally sold on is when you want to do out of control chaotic oscillations - ie; crank the feedback right up to max, and let that pupper squeal.
I don't think it sounds as good as a lot of the competition. The DD500 doesn't seem to soft-clip the output, so what you end up with is a really harsh horrible sounding hard clipped mess. I'm not sure if it is the DAC clipping or what, but it isn't pleasant.
So if you wanna do those kinds of sounds, you need to be really careful, and I'd
probably recommend another delay.
But, for most of your bread and butter delay sounds, the DD500 still to this day punches well above its weight. The ability to put a 4 band EQ in the feedback-path of any delay model is a tweaker paradise. The only other device that gives you that much control are the Fractal units - at least, the Axe3/FM3/FM9/VP4 generation.
DD500 can also run two presets at once, which is really really cool.
The TC Flashback stuff is quite nice. You do get a lot of control via the Toneprint editor, but it isn't the nicest thing to use, and dealing with banks and patches kinda sucks. The Plethora is a really cool (and quite cheap when it is all said and done) Swiss Army Knife of a pedal. The pitch effects blow chunks.... but the delays are great. Really good in fact.
I don't like the analog algorithm on the Timeline very much. It just doesn't do that nice crisp analog delay sound, and it won't brighten up, and the oscillations turn into muddy terror (that one is for you
@Cirrus ) but the other modes are quite good.
Line6 have some fantastic delays, but strangely, I am not a fan of their bog standard digital delay. It doesn't echo away enough and the parameters are tricky to balance. Like, 12 o'clock on the feedback knob on the DD500, and you get around 14 echoes. But 12 o'clock or rather 50% on the Helix Simple Delay, you get about 5 or 6. When I was using Helix as my primary effects platform, this was always a big battle for me.
Source Audio... let me pimp my video:
I still think those tones are some of the best you can get from a guitar pedal. What lets Source Audio stuff down (and you might not care) is the preset spillover and midi switching side of things.