This little boutique version of the TR-808 manages to nail the sound very closely indeed. I didn't have an original to do a side-by-side comparison, but if you're interested by the unit you'll find decent critical reviews from folks like Sound on Sound have done exactly that and found that it's very close indeed. For me, it's certainly close enough to be worth spending a tenth of the price of a used 808 :-D
In terms of handling, you're somewhat at the mercy of the 808's original workflow – which is not entirely intuitive. It's taken me a few hours to get my head around the procedure for mapping out beats and then stringing them together. But the unit has the definite virtue of minimal menu-diving (it's basically only some of the more esoteric settings and effects that are hidden in menus), and the one-control-per-function vibe makes programming pretty easy once you have the hang of things.
The "manual" is an A3 sheet with the basics printed on it, which feels a bit cost-cutting (a little booklet would have been much nicer), and I wish it had a proper PSU rather than just batteries or USB power. But those minigripes aside, I'm really liking it :-)