Just some info. not spelled out anywhere obvious related to ESS in Filemaker 12.
1. The record cache is now much larger, so you should be able to have quite a few more fields in your ESS table without running into issues. This is driver and platform dependent, as far as I know, so your mileage may vary.
2. We can now Commit records and over-ride the "Another User has modified the record..." dialog via Script steps. Yeah!
3. The new Execute SQL function has no direct link to ESS, but it does work against ESS Tables. BUT BEWARE, if you execute functions against large tables, the perfomance is debilitating, as the data is evaluated in the context of FILEMAKER not the SQL database, as such, the data must first be loaded into Filemakers cache, then evaluated. It does not use indexes or anything else from the SQL database that would speed these functions, so USE WITH CAUTION.