Finally I could take out some time to backup my data and went for a firmware upgrade. I have been using the F8 version since i have gotten the phone. No major problem for me except the lack of chinese input and the stopwatch.

Pretty excited about the new firmware, since i skipped 2 upgrades, there are huge changes and improvements from F8 to H3. Still in the midset of playing it, would report back here on the chances next time :)

Below is the anatomy of the firmware number
The firmware code is split into individual sections:

i900 - > model designation (SGH-i900).
XX - > region / network carrier designation (XX = Spain - open Market).
H - > release year (H = 2008).
K - > release month (K = November).
1 - > version number.

- Region codes:
BD Cyprus, Greece
CP Finland
DB Vietnam
DC Thailand
DD India
DT Australia
DX Indonesia, Malaysia, Philippines, Singapore, Vietnam
DZ Malaysia, Singapore
JA South Africa
JC Algeria, Morocco, Nigeria, South Africa, Tunisia
JP Arabic
JR Arabic
JV Algeria, Egypt, Iran, Iraq, Kuwait, Morocco, Nigeria, Oman, Pakistan,
Saudi Arabia,South Africa, Syria, Tunisia, Turkey
MT Switzerland
XA Austria, France, Germany, Italy, Netherlands, Switzerland, United Kingdom
XB Denmark, Norway, Sweden
XC Portugal, Spain
XD Croatia, Czech, Hungary, Slovakia
XE Bulgaria, Estonia, Kazakhstan, Latvia, Lithuania, Russia, Ukraine
XF Bulgaria, Croatia, Romania
XX Austria, Belgium, France, Germany, Hungary, Italy, Spain, United Kingdom
ZC China, Hong Kong
ZH Hong Kong
ZT Taiwan

- Network carrier codes:
AE SFR, France
AI Tim, Italy
AM Vodafone
AN E-Plus, Germany
AS KPN, Netherland
AU Mobilkom, Austria
BB Tmn, Portugal
BF Optimus, Portugal
BG Telefonica, Spain
BM Swisscom, Switzerland
BN Amena, Spain
BO T-Mobile, Germany
BU Vodafone
BV Orange, Switzerland
BW O2, United Kingdom
CD Proximus, Belgium
CG Telia Mobitel, Sweden
CH SingTel, Singapore
CK Tele2 Comviq, Sweden
CT Tdc, Denmark
CU One, Austria
CV Telenor, Norway
DT Optus, Australia
DV Telstra, Australia
EF Celcom, Malaysia
JB Vodacom, South Africa
MD Telia Sonera, Finland
MJ Vodafone, Italy
MM Tele Ring, Austria
MV NetCom, Norway
NA Nrj, France
NB Tele2 Norway, Norway
NE H3g Nordic, Sweden
NP H3g, Italy
SS Vodafone, Japan

Release years:
D = 2004
E = 2005
F = 2006
G = 2007
H = 2008
I = 2009

Release months:
A = January
B = February
C = March
D = April
E = May
F = June
G = July
H = August
I = September
J = October
K = November
L = December

i900DXHH3 would mean that its a i900 firmware for Singapore market, third version released in August 2008