[RTL SDR] Has anyone done testing on these cheap SDRs?

[wb4jfi at knology.net]

I now have one of these DVB-T USB tuners (Terratec E 4000 version).  I'm 
wondering if anybody here has done some extensive testing on sensitivity and 
dynamic range?

Also, has anyone used the HF upconverter with these?

It would seem that with an only eight-bit A/D, the dynamic range would be 
rather limited.

I also have a couple of similar modules, but with the RT820(?) tuner 
instead.  I plan to take one of them, and do the mods found on the net to 
convert it to a direct conversion A/D.
Terry, WB4JFI