Vertical banding mostly.
Also poor performance with PAL DVD's (noisy picture).
Don't get me wrong though... for the price it was very good. You may not notice or be able to eliminate the faults I noticed.
It is also the quietest PJ I have heard (or not heard).
The lens shift really works well and it is quite a cute design.
It also has good menus and connections.
It's all about what you are happy with.
For me personally... I noticed these picture problems all of the time and I began to look for them as soon as a movie started. It ruined the experience. You should be able to relax... crack open a beer and just enjoy
I don't notice any problems with the HS20 picture... it's just a pleasure.
It's a shame you can't demo them.
For what's it's worth... if you came to me for advice and you had the money I would say go for the Sony. You know the picture is going to be the best you can get from an LCD at the moment (without spending silly money), it is very well built, has HDMI and DVI, is fairly quiet and has good features.
regards

Doc