Interface: A little guessing as to where the buttons really ae but once you find them, they have a name pop up that tells you what they are. that's all I need.
Sound: Interesting. Makes the tinniest acid lines (as that has been what I have been using it for so far) into a more phat and grungy sound. Don't know about authenticness, but I'm finding it a bit malleable for my purposes.
Features: Not much, does some weird things here and there which might interest you. But not really. But eh, it's a delay box, not much I'm really looking for in it.
Documentation: Eh, for me, it doesn't need it but there's a manual which you're supposed to read before using. Oops!
Presets: No presets, but it's not like you really need them for this thing. Play with it.
Stability: No crashes so far, which is a good thing, I reckon.
Dollar value: It's free, so it's all good. Time-value to download and to plunk around with it? It's definitely worth a try, you might like it. It's a simple little tool which has cute little quirks.