Roland,
As I have not seen Barco's internal scaler I cant comment. I have however seen their internal doubler and would suggest to anybody considering this that a good progressive DVD player such as the Panasonic RP-91 (which is one of the very few that does not have the chroma-bug) would be a better alternative than the PJ's optional internal doubler.
Of course as you say this would only deal with the DVD side of things which is probably what people enjoy most anyway.
DVD being the source with the best native resolution available to us in this country (True HD digital Tapes shortly-perhaps) .
As an added bonus the Multi Channel sound on dvd is also unique (apart from LD). I set up his Denon 3802 to output DPL2 (which I found worked marginally better than DTS NEO) for everything other than DVD but of course this was still a shadow of what true DTS or DD sounds like.
I also installed a motorised digital satelite system (Humax) for this guy with around a zillion stations most of which would need a translator.
Sky also turned up and installed a digibox which together with the Humax system I later upscaled using an old Quadscan I have lying around.
All I can say (and the customer agreed) is that when you upscale what is essentially a rubbish source, you end up with more rubbish.
In this case the client was happy to watch Sky and the Sat stations in its original form.
Anyone got an old S&N lying around for me to try with sky

Richard are you listening????
Eric