The GPS is more than just a software issue it seems...there's a hardware/ software fix posted on XDAdevelopers...google it; should be easy to spot. The catch is...any changes u make to ur hardware voids ur warranty...lolz

my phone lock fast also, don't have issue with it

I can name three things where samsung went wrong with sgs:
1. Lag
2. Gps
3. Build quality

- SGS had a horrible lag and sluggish performance due to usage of poorly written filesystem (RFS). It is now greatly improved in the froyo 2.2.1

- samsung uses a second rate gps chip. However, mine works so so. I got 20m accuracy on the road. Remember, a gps lock means nothing if the phone cannot maintain connection. To truly test the gps, you'll have to test it on the road. The latest 2.2.1 also has helped a bit.
I use voice navigation feature in the phone and it flawlessly helped me to to my destination. Unfortunately, I required a bit of fixing to achieve the best possible gps performance. You wouldn't care what chartcross' gps status says if the phone can give you what you want - navigation, right?
FYI, Samsung nexus s has a better gps chip. Probably they have learned a lesson. Anyhow, such problem shouldn't have existed in such a premium phone. Same goes to iphone4 with its external antenna.

- Plastic case? They shave off few grams and make it light. Some people do not like it because it will feel cheap when holding the phone. But I do not mind it at all. To me, the super amoled screen is just way too gorgeous too look at and it outweighs the cheap plastic.

However, I don't think you've wasted 2.6k on the phone. Try and learn what it can do and you'll be surprise!
Also, don't take mainstream reviews with a pinch of salt. What you should listen to are user reviews. 
Or go to Settings > About Phone. Baseband version shows what modem you have.
Depends on what flash. If flash advertisement, ok. But if the whole website is flash, then it will be sluggish.

---

Added on January 18, 2011, 7:26 pm
It is gps chip (hardware) issue. which kind of modem you are having also affects gps performance. I have posted a link on a review made by pele78 in xda developers. It is just a few pages back. Try each one of the modem and see the result.
If wifi issues, then it is the modem.

When did you get yout phone? 2.6k is way way way way way too expensive. Even 600usd is only RM1834. I got my sgs at 27500rupees = RM1850 only (in october).

I didn't recommend sgs to my parents, they got htc desire instead. samsung didn't put much effort to lock down the phone like htc and motorola did. So it is almost a hacker's dream, and I love it. But for normal general population, htc sense is more user friendly.

Good to hear that!

@holypredator
Have u tried different modem? When i was in dxjpe, the gps connection is not so good. Barely get the reception but cannot lock in. After upgrading to jpx/jpy/jpu modem, the gps seems to be working much better. Different phone might required different setup.

no need to reinstall one by one.. use Titanium Backup.. easily can backup.. and easily install em at all..

1) Darky's Page
http://forum.xda-developers.com/showthread.php?t=814091

2) Speedmod
Tutorial: http://touristinparadise.blogspot.com/2010...to-install.html
Download: http://touristinparadise.blogspot.com/2010...d-speedmod.html

3) Tweaks you can get it from recovery mode after u've flash speedmod..

As jujx said, flash to v8. Heck, v8.2 is going to be released soon

If you enable the tweaks, you will have a smoother ui and perfomance, and better battery consumption. Just enable those with 'R' which means recommended. 

Noob is ok, its better you take initiative to learn rather than complaining here.

So to start, what's your current firmware? Do you want to do clean install ?

TO Holypredator:

Before even trying to flash, PLS MAKE SURE ur 3 BUTTONS is function ie.

when u pressed Vol up + power + Home --- > Recovery Mode

when u pressed Vol Down + power + Home ---- > Download mode

If u dun have this, dun attempt to flash, else u will come back with lotsa problems.

Some phone do not have 3 button combo enabled, so make sure you check if your set has 3 button combo enabled.

Mine came with 3 button combo disabled, bricked once, went back Samsung, and they replaced a board with 3 button combo enabled 

don't have to root. you just need 2e recovery/cwm

get the update.zip from darky's website

yeah, cwm is kinda useful

Very easy. First you flash speedmod kernel using the instructions given in the link by gajahwhite. Enable all tweaks or maybe lagfix too.

See if you like it. Don't like or want to explore further, then you download Darky V8.0 non wipe version and put it inside your /sdcard. Flash it using CWM. There is a tutorial video in Darky page (refer to the link gajahwhite given you).

After you have all the files ready, flashing speedmod should takes you less than 5 min. Flashing Darky V8.0 should takes you less than 15 min. Then you are done!! 

Superuser means your phone is rooted. Rooting is needed for apps like Titanium Backup, Adfree and etc

Get the update.zip, then place it into your internal sd. Next, boot into the recovery mode and apply update.zip TWICE. You'll get your 2e recovery by then to install the darky's rom

Err, darky's v8 comes with a voodoo kernel with lagfix disabled, meaning after you install the rom, your existing speedmod kernel will be replaced with the voodoo kernel. You gotta flash the speedmod kernel again after installing darky's rom. Remember to disable any lagfix/tweaks before applying darky's rom

You can root after apply speedmod kernel. Easier since it has everything, 2e recovery and CWM all bundle inside.

Forget about update.zip, flash speedmod using odin first.

enable tweaks and lagfix in 'advanced speedmod kernel'

enable all tweaks with 'R'
enable lagfix
click on 'system'
and reboot

then, a menu will pop up asking if you wanna change system to rfs or ext4, pick ext4

it's your choice whether you wanna enable lagfix or not