There is a lag fix for Galaxy S and Galaxy SL, have you applied it?

No la.

This is the lag fix for SL I mentioned, also contains instruction how to root SL.
http://forum.xda-developers.com/showthread.php?t=1034895
(I should mention that I haven't tried the fix yet)

I tried the root and lagfix above, works for my SL. Quadrant benchmark ju
mp from 850+ to 1700+ after lagfix. So far everthing smooth.

I have the same problem in win7 64bit. Previously I read somewhere it's because of 64bit, should be no issue in 32bit. If I remember correctly, there is a fix for 64 bit, but i couldn't find it.

Just FYI, I bought mine from a Samsung partner shop, they give 2 years SME warranty.

Ok now my phone can finally can get gps location lock.

Here's what i did:

Go into Lbstestmode
- undo all settings to original
- then press 'Delete GPS data'

Reboot phone.

Get out from building.
Go into Lbstestmode and press 'Get Position Test'.
Wait and phone detects satelite one by one.
After sometime, it will timeout. press 'Get Position Test' to restart test again.
Repeat until it can identify your position, at this time, it detected 7-9 satelites.
For me the whole process took about ten minutes.

Run more tests, and it only took about ten seconds to lock position.

I use moboplayer can play mkv. 720p video can play also, but lag, I think this hardware limitation.

In terms of graphics performance, I doubt that Adreno 205 is superior than SGX530.
I have both Galaxy SL and Incredible S (which uses 1ghz snapdragon and Adreno 205). I compared the scores of Antutu, An3DBench benchmark, I found SL is slightly (~5%) superior than IS in terms of 2D and 3D graphic scores.
I thought there is something wrong with IS, so I checked the benchmark scores of Desire HD (also Adreno 205), about the same and IS.

I think other branches also have, because i bought mine from novacell in penang. Same price, but got choice of brown and white.

No. only got choices of european languages.