I've had the DVB680 box for over a year; it was one of the first budget boxes available. It's come down in price considerably since the 2010 World Cup.
The goods news first.
The essentials are in the box and it's fairly easy to setup, if a bit on the slow side.
The HD picture and and sound quality are good on our Sony Bravia.
All Freeview HD Channels can be received, which in England are BBC One HD (Channel 50), ITV HD (Ch 51), BBC HD (Ch 54) and Channel 4 HD (Ch 52). For viewers in Wales, Sianel Pedwar Cymru Clirlun (S4C Clirlun on Ch 53) can be received. (Clirlun translates as "clear view").
All the usual SD (Standard definition) and radio channels are also available, and if a TV programme is being transmitted simultaneously in SD and HD, the programme guide will inform you of it, so you can choose.
The not so good news.
The box is generally ponderous, responding slowly to inputs from the remote, including re-booting.
When coming out of stand-by, the picture is fine, but sometimes there is no sound, with an error message from the TV about an unsupported device. Re-booting the Bush resolves the problem, but takes 2 or 3 minutes.
The remote could be better designed, and patience is generally required when using it as the set responds less than promptly at times.
The Electronic Programme Guide is OK, but not as slick as Sony's, and there is no facility to bookmark a future programme.
Setup asks for your country, which is generally seen as fine. However we are on the border where we receive strong signals from both English and Welsh transmitters. The nuisance is we have to pick one or the other, and not have access to both simultaneously.
It may seem trivial, but the stand-by LED is very bright, far brighter than it need be, and is very noticeable in a dark room.
The bottom line is that once you accept these minor annoyances of a budget box, the picture and sound are very good, so you can relax and enjoy your chosen HD programme.
However, if I was looking to buy an HD box today, I'd probably look more up market for a slicker box.