I have the Tupta600 and PW5. Not much I can add really really. I didn't do any comparisons.
The only things I have noticed to date, which I believe are problems, are the "Auto" aspect mode and the AV selection.
The auto aspect mode seems to do a duff job of selecting the correct viewing aspect for the source. On terrestrial TV, which is only where I've noticed it so far, you more often than not get very narrow bars top and bottom before the "Auto" has kicked in and adjusted the aspect. Why the bars are there I haven't worked out yet. But what makes it worse is that that Auto aspect instead of increasing the vertical scaling and squashing horizontally or chopping the sides off, it increases the size of the picture in all directions and chops all sides. Go figure !
The AV input select also seems a bit suspect. Firstly there are no discrete codes, a pain if you want to set up remote macros to make it easy for the wife and kids. Secondly it seems to get locked on to the wrong signal within the scart. You should be able to cycle through AV1/AV1s AV2/AV2RGB etc etc using the AV select buttons, but instead once its displaying AV1s for example the cycle button starts switching aspect instead of the AV input mode. I guess the only way to fix this would be to disconnect the unused connections in the SCART to prevent them being selected.
Picture quality seems perfectly good to me, but how much it has been compromised by the Tuner I cannot say.