Just thought I would chime in and say I am not noticing any loading problems with 12v3 on either OSX 10.8.2 or Windows 7.
Both are consistent with 11, at around 5 seconds to the menu and 11 seconds to fully open the same (but converted) solution files.
Did you perform an update? Perhaps it may be worth trying a clean re-install and patching again, unless you are able to download a 12v3 install
Ive not had to do so for a long time, but iirc you could download the trial and activate, thus getting a pre-patched install.
Of course it could be related to something else, but thought I would share my loading times.
Thank you for the post.
SWS's suggestion of an uninstall and reinstall is a good one. My load times seem consistent with FileMaker Pro 11.
Are you launching the program from the dock, application's folder, or by double-clicking an existing .fmp12 file?
Do any other programs seem to be launching slower?
Please let me know if this resolves the issue, otherwise we can discuss next steps.TSFalconFileMaker, Inc.