Just look wat happen to the batches b4 the windows nokia 920 series..the lumia 900,800 if i recall cannot be updated to latest windows OS.
Yeah..arc is good.serve me the longest..8 months.before i feel the battery kinda wonky..sold it off and get a Note.
I used SE Arc as it is and am fustrated with the size of the internal memory. So after I upgraded from Gingerbread to ICS, I rooted and flashed the ROM with a hacked kernel, installed Link2SD to make use of external memory allocated from SD card. This allows me to extend its usage till now. But I can do with a faster phone with the new contract.