The price for this is astounding. The picture quality for HD channels is excellent and I use this on an internal aerial but that will of course vary according to your location and your aerial. Some had lip sync issues but no problem with mine. I updated the firmware anyway which was quick and painless. Two version upgrades were available from August website.
Don't expect total perfection for such a price but you can attach a USB flash drive for recording if you wish, but I don't use that so cannot comment on it. I just wanted it to add HD channels to a bedroom TV which had freeview, but not freeview HD. For me it works perfectly for what I wanted it for.
The channel guide for HD channels doesn't work but the Manufacturer does point that out clearly on the website and the instructions.