GT-I5503T here from NZ, upgraded to Froyo 2.2 about 2 weeks ago using the USA GT-I5500L firmware.
Same with others, there are a few issues. Wifi disconnects/disables at random, compass doesnt work correctly. Overall though, wifi can be reconnected and how often do you use the compass... really...
Until the offical Froyo versions come out for each of our countries, the USA is very usable and the positives well outweigh the negatives.
Unlike a number of other people, my battery is pretty great. Been running for 39 hours so far on this charge, 43% remaining - moderate usage overall, heavy at times.
I have had probably 4 complete charge to complete discharge cycles - and a number of top up charges.
Phone is overall faster with Froyo too.
I use SetCPU for Root Users to scale my CPU to be 'On Demand' and let it run from 245mhz to 600mhz, rather than having it fixed on 600mhz. Seems to work pretty good.
Very much looking forward to this Cyanogenmod for these phones.
Keep up the good work.
Cheers
J