I have a Xtreme PVR. Its my first receiver as I'm new to satellite TV so I don't really have anything to compare it with. Having said that I am reasonably happy with it considering the features you get for the price.
There are issues with the digital output (TOS) on some earlier models. I.e. Dolby digital apparently stutters. These machines need a hardware upgrade to fix the problem. The models made after April are fine.
I have an Aston rotor but I cannot get USALS to work, although I can automatically rotate my 78cm dish when selecting 'Motor' in the Settings menu, manually rotating the dish and storing each position.
One great feature is that while watching a broadcast, you can hit 'rewind' button just like when watching a VCR. This is apart from the timeshift function which kicks in when you hit the pause button. In the latter case the TV picture actually pauses. Hitting the pause button a second time starts playback from the moment you pressed pause the first time. Its possible fast forward and rewind when using the pause function.
One quirk I found was in the timed recording menu, you enter the start time and the 'duration'. This took me a while to figure out after filling the hard disk with hour s of material. I am used to entering the end time on my VCR, not the duration. )(-red
The menu's are pretty clear and easy to understand.
I am in the Netherlands (ex pat) where Canal Digitaal rule. The built in U-CAS accepts the Canal Digitaal mediaguard card without any problems. I have heard that pentacrypt sometimes hangs on Canal+, tetracrypt is supposed work fine though. Just in case I installed tetracrypt.
Picture and sound quality are good, even in bad weather. I normally get around 84-88% on Astra1 and Astra2.
The manual, is crap. It basically just tells you have to switch on the receiver and skips through some of the menu options. Some features such as USALS only get a brief mention. Manuals can be downloaded here:
http://www.xtreme-stb.com/db/downloads.asp
On the whole the Xtreme is a decent machine. As with anything you buy these days. Ask the dealer if you can return it with a full refund if it doesn't meet your expectations...