Bro Soken,
Read your post at the chinese forum about buying a700 in china and about your disappointment of a200 when you bought it intially, thinking that you were being cheated to buy it as supposed to your initial d60 purchase.
Actually, I was also pondering between D90 and 450D when I was shopping for a DSLR. After trying out at the SITEX show last year, I bought the A300 in the end for it's good liveview (better than both D90 and 450D), it's more solid build (compared to 450D) and affordable price (compared to both).
Same as you, I always told myself why I stupidly bought a Sony DSLR when I saw the results from ISO400 and above. It looks bad, which is like a little better than my Canon PNS camera...though I can't create a nice bokeh with my PNS...which is already a300 has something to cheer me on using it.
Buying some prime lenses like 50/1.4 and sigma30/1.4 made me stick to it for a while (about 6 mths) and I have used my a300 for 2 important events (my son's 2nd birthday and family trip to paris) that gave me a good 6000+ good quality photos...
When these 2 events were over, my mind then started to wander wild again, bringing back the urge to try out the other 2 brands for better ISO performance.
However many brothers here had advised me that my solution was to get a700. I didn't believe so in the beginning as thought how much improvement can Sony do on a body that is only 1 grade better than my a300.
Anyway, i finally took the plunge about 2 months back and got a 2nd hand a700 after selling off my a300. Initial tests show really better ISO performance (at least 1 stop better) and much faster and accurate AF. I even got myself a cz1680 to try out how good a700 really is.
After trying out for 2 weeks, I still couldn't get my mind off 500D and D90 as probably I think with greater anticipation, my threshold for quality was even higher. Luckily one of my business associates actually gave me a D90 as a gift on a sudden occasion and I was fortunate enough to test both a700 and D90 side by side.
As i mentioned earlier, D90 definitely has better ISO performance (about 1 stop) and you can see minimum noise at shadows and mid-tone areas as compared to Sony with quite obvious noise at darker areas but only when you view at 100%.
However, D90 do have quite noticeable noise at brighter areas at ISO1600 and above which A700 shows completely clean output on bright tone areas even at ISO3200.
So it's like each has it's own flaws of noise at different areas.
The killer feature that made me quickly sold off my D90 at minimum loss was it's AF, which is definitely not as inituitive as A700 and not as quick to react. As I think eye-start feature in Sony is actually working it's advantage over other competitors.
After also doing some shootouts with my friend's Canon 500D with his 24-70L lens, I am finally convinced that A700 is the camera for me, with good sharpness (even with a normal 18-250 lens with cheapo Tokina UV filter) that can beat 500D and good AF for 70-80% sharp pictures (as compared to D90 30-40% only) of my son.
With these results, I have since invested more in Sony with F58 flash, bought back another 50/1.4 lens and looking to increase my arsenal of gears with Alpha to prepare for more new bodies coming up...
:devil:
Pardon my long story though....:sweat:
, haha, already got buyers for my a200, will join the a700 family in less than 15 days. 
