I think that it is a good thing were are not seeing so many posts on this TV, I suspect that it is because there are fewer problems (or perhaps less descriminating owners). I had the chance of going with the 960 or 955 (for about $120 more (though the XBR's were floor models) and I still went with the HS420 because it is the tried and true original Trinitron CRT (in terms of stripe pitch and cathode emitter surfaces).
I am glad I did too as every 960/955 had a problem that was unacceptable to me (focus, geometry, or bad color impurities in any combination on every one). Plus, having used NEC XM/XP and 3PG monitors (all 29" CRT Presentation Monitors) I knew that having an ultra fine dot pitch is not always a good thing. There is always a trade off, with the NEC's it was brightness, the 3PG was far brighter and more vivid but had a bigger dot pitch than the XM/XP29. With the Sony XBR models Sony used a different phosphor coating to compensate for the drop in brightness, it worked but the consequence is more trailing on high contrast scenes. For screen sizes of 30" and 34" I just do not see the reason for the SFP CRT, if it something that you cannot tell from more than 3 or 4 feet back and you sit further away then it almost worse to go with the SFP.
Anyway, a little tweaking in the SM should get rid of your bowing issues. Though you must go in with realistic expecations, widescreen CRT's are not going to have perfect geometry, focus, and even convergence everywhere on the screen (this has alot to do with the flat CRT). Thankfully, I see very little geometry errors on my HS420 (only at the upper left, which is understandable considering the retrace patch of the beam; anyway, the 960's were probably 3 times as bad as mine), The way I see it these little issues are a small price to pay for such great picture quality.