I've been following this thread with interest because I also bought one of these 'cheap' DVB-T2 tuners under the assumption that the linuxtv wiki page was correct. Two days after I placed the order, information emerged that it's a bit wonky on dvb-t2 in linux.
Anyway, at the risk of sounding unhelpful there's very little point in switching between versions of any distro in the hope the tuner will just start working. It's not going to work until the person debugging the linux driver has made more headway - and then tvheadend will need to incorporate the changes he eventually comes up with :-)
What everybody needs to do is (eek!) get on the commandline - SSH is great for this - and grab the output of the dmesg command upon plugging the tuner in, then grab the same output again when attempting to get a signal lock (i.e. during a w_scan or tzap command). The more information the developer has to work with, the better.
I'm starting to suspect (though I hope I'm completely wrong) that maybe this tuner's hardware just isn't up to the job. Maybe under Windows (especially with the junk software it comes with) the PID filtering is done on the tuner, meaning only one channel's bandwidth goes across the USB bridge at a time. Under Linux, the kernel driver is expecting to put the whole transport over USB & it will do any PID filtering. So, 10-15Mbps.. works fine.. but 40+Mbps doesn't. As I've already said I hope I'm wrong, and that tweaking the driver will fix this.
I've had a go at translating a USB analyser capture of the tuner running in Windows to see what's going on - and then comparing that with what the linux driver is doing, but it's tough going. Those linuxtv guys make it sound so easy!
