AFAIK all reports point to the hauppauge having better reception, yes its 2 usb tuners on a pci board with a VIA usb controller.
Now with the TVServer has a delay setting before it detects TVCards (mines set to 20 secs) the slow resume of the usb tuners is overcome.
There was another problem with decomposing the Tuner graph, when both tuners where used at the same time, this was fixed in svn 19069 (update for MP1RC), this only ever affected TVServer users, but as TVServer has so many more advantages over the inbuilt MyTV which is no longer supported by the MP team.
The main advantage is being able to record without MP running (
TVServer Monitor is a good systray app for monitoring what is going on) with the pc turning itself in\out of standby for recordings.
Also the ability of recording every channel that is broadcast on a single transponder, for me that means a possible 12 recordings (6 channels per transponder).
Hopefully this has answered some of your main questions.
Apparently the pinnacle card is the same (drivers at least) as the
blackgold 6in1 card, so you may want to do some research, although i have not heard anything particularly bad about it.