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Hi again, I wonder what the difference is between Xperia U ST25i and ST25a modelnumber? And does any of them gets ICS faster maybe or are they just same?
some of ST25a have ICS right now ST25i is underway this week.
sorry for my bad english!
A for America, I for International. Difference is just in Baseband support.
network bands...
Sony Xperia U ST25i:
UMTS HSPA 900 (Band VIII), 2100 (Band I)
GSM GPRS/EDGE 850, 900, 1800, 1900
Sony Xperia U ST25a:
UMTS HSPA 850 (Band V), 1900 (Band II), 2100 (Band I)
GSM GPRS/EDGE 850, 900, 1800, 1900
allright i guess both are same, but what does mean with those brand V and III etc?
As I understand it, band is frequency on which network connection is running - phone is operating on it. With 2G is no problem but using 3G/UMTS the phone with incorrenct band version will not connect in some regions - in this case America vs Other world. I found somewhere some info that you can apply ST25a version to 25i version and just modify some file that contain info about bandwidth and everything should work fine....but it's risky to try it on my own phone... 
the "a" variant will work on North America (AT&T), Australia and South America, the "i" variant will work with most countries 3G even some in North America (tmobile)
you can flash either or firmware
ST25i firmware to the ST25a, the phone ST25a will work as a ST25a but with ST25i name.
yes that's a great link, what about it? Do NOT confuse
GSM (2G) with UMTS HSPA (3G/H)
The differences is what is mentioned above, concerning the basebands.
They're simply aimed for different markets, but contains the same spec's otherwise. 
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