Ok so instead of looking for a new card I have spent some hours browsing for tweaks and setups for my PVR 150 card.
I found the usual settings for turning down/off the temporal and spatial filters but I had already done these.
Then I found someting new : These registry settings that turn on the comb filter (not entirely sure what this is

) that by default
is turned off on the hauppauge 150. It is turned off due to the introduction of dot crawl on the picture.
Anyway I added this and found it greatly enhanced my picture, to the extent that is is comparable to that if I plug my DSTV
decoder directly into the TV, which was my 'holy grail' of TV tuner setup.
I do notice the dot crawl effect on edges of static logos (especially if they are red) but its very minor and IMO does not detract from the picture.
So, here are the settings :
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\hcwPP2\DriverData]
"HcwMakoReg_SrcCombCfg_AND"=dword:00FFFFFF
"HcwMakoReg_SrcCombCfg_OR"=dword:20000000
"HcwMakoReg_CombCtl_OR"=dword:001F0000
"HcwMakoReg_CombCtl_AND"=dword:FF00FFFF
"HcwPALCombFix"=dword:00
I would be interested to know what you other hauppauge users think of these, so give them a bash. One may always deleted
the registry settings if you don't like it.
The link I got them from is here
http://www.shspvr.com/smf/index.php?topic=9170.0