Your T5750 tested similarly to my T6400 2.0GHz / 2M Cache / 800MHz FSB except it scored 5.5 on both CPU and Memory
The T8300 which finally arrived in todays mail scored 5.9 in both top lines
And I always get a "5.9" on primary Hard drive speed, but then again I have a 500gb 7200rpm WD "Black" drive, that made a larger improvement in performance of this notebook than everything else I've ever done combined.
Not that Windows Experience scores are anything close to important, but I feel real good about bumping from 5.5 to 5.9 for a whopping $15
The 5-ish second improvement in boot-up from the new CPU time is "nice"
That's better than the improvement seen going from 2 x 1gb RAM modules to 2 x 2gb Ram modules
I'm not sure that there'd be as much performance increase from a T9300 or T9500, as I'm pretty sure that any further increases are going to be pushing hard against "diminishing returns", so I'm not in any rush to buy one...
But I do have a customer with a dead High end Sony Vaio Notebook that says it's got a T9500 in it (I just had him reading the specs) along with a BD-RW drive (and the little uPCI card to run it) and if it is unrepairable
I may just get one as an interesting bit of another "carcass"
(I said I was a "Vulture" didn't I?)
Interestingly we are both running 32bit Win7 Ultimate.
I got mine legally via a Faculty/Staff educational installer.
(Don't work for them any more, but nobody told me I had to give it back:)
Why did you go with Ultimate?
BTW, while I was typing the reply above I had a FULL Virus scan running on the computer, all volumes, this typically runs just under an hour and you can see the scan pause on larger files.
It pauses a whole lot less now and the full virus scan finished in about half the normal time.
I guess the faster CPU really was worth the $15:)