I would totally buy MS5 EX if they were more timely with the updates... but their current record instills no hope in me.
Wouldn't be surprised if the EX version they release is based on a very outdated build of CSP EX. If it's based on 1.2.3 I'd be very surprised, yet elated.
They need to release patches within a month of the Japanese version, that's not asking much when trev can crank out great quality english patches in days, and we love trev for it :d