I've got a couple of PCTV sticks (290e and 460e, I think - one DVB-T2 and one DVB-S2) - as well as the WinTV-Nova-TV (old version for DVB-T) - all work well. You need to watch your kernel version, as supports gets better in 3.0+ (shouldn't be a problem if your Linux distro is less than a couple of years old).
Yes, I have signal quality on the 290e on tvheadend 3.5.23~g4724e01-dirty; the 460e, not sure, as that's on an older version of tvh that doesn't report the SNR. All I have is the signal strength in Configuration/Multiplexes.
EPG works fine, that gets picked up from the provider if tvh has the right OTA module (e.g. Freeview or Freesat in the UK). Otherwise, you can still use XMLTV.