I just recently switched from Win XP 32 bit Activestate perl 5.10 to Win 7 64 bit Strawberry perl 5.14.
I made the switch from Activestate to Strawberry perl because of the reduction in up version ppm support for perl modules. By that I mean that the basic cpan or cpanp install can work across multiple perl versions for many modules but Activestates ppm support which is tied to the perl version will often be months later than the module release. The major downside here has been mixing it up with any XS modules. This has mostly been an issue when the module looks for make or nmake rather than the Strawberry perl dmake. The upside is now my install reports go to the CPAN testers (mostly).
Ultimatly the largest barriers have been Tk and DBI-> Access. Tk doesn't ship with the base Strawberry install and won't pass all tests. (I solved this with a forced install). My DBI connection to some prototyping Access databases that I use still isn't up yet. I suspect that the root cause here is on the windows side not the DBI side since Access requires that you set up an ODBC handle. I have a 32 bit version of Access ($work won't pony up for 64 bit Office yet even though moving forward 64 bit systems are default) on a 64 bit system and that seems to be the disconnect. I so far have resisted downgrading Strawberry perl to 32 bit with the thought that it might finally be time to move all my database work to PostgreSQL.