nickyvicar,
Summary as follows:
Buzzing sound emitting from back of set (although only experienced this on the 32ZD and not my 36ZD). If you have this problem ask for a replacement.
Shadows at either side of the screen. This is a "feature" of the 36ZD and there is no solution. It varies from set to set, so if you can put up with it/even notice it, then keep it.
Horizontal geometry issues. i.e. The black bars of a 2.35:1 film will bow/bend up/down at the top/bottom of the screen. There is no way to fix this in the service/designer menus, an engineer can only rotate the picture, not straighten these bars.
Vertical geometry. This fault is most noticeable in 4:3, 14:9 modes; the black bars at either side of the screen will not be straight/parallel/the same width etc. This can easily be corrected in the service menu, either get an engineer out or do it yourself. I would advise using an appropraite test pattern to obtain the best results.
Hallowing. Most noticeable with white icons on a black background, the icon will appear to be out of focus with a surrounding white "mist". Again this varies from set to set, so if you can live with it then keep it.
Flaring. Most noticeable with white moving objects on a dark background. The objects will leave a trail behind them as they move around the screen. This varies, see above advice.
NTSC Progressive scan from a dvd player causing a flickering/pulsating effect. Get a replacement if this happens.
NTSC Prog scan from a Gamecube causing distortion on certain games with bright areas (sky etc). I'm not sure about this one, but if you don't have a Gamecube, problem solved!
Rainbow effect. This is similar to the distortion caused by holding a magnetic source close to the TV (like a speaker), you should see discolouration/distortion. If the effect is still present after a thorough degaussing, get a replacement.
When the TV is delivered check for damage to the box and whether it is sealed with Toshiba tape. If it's damaged or sealed with brown tape, refuse delivery.
I cannot comment on RGB Direct, however my experience of Robertsons Online has been more than satisfactory. I have had three replacements (so far) with no arguments; they are very helpful and friendly, although other people have had different experiences.
I think I've covered the majority of faults with this set, you might be one of the lucky ones; there are people with "perfect" examples, so if you do experience any of the major faults above (guess what) ask for a replacement.