Were VBA and Bizhawk the only 2 emulators tested? I only ask because they're the only ones discussed, and if they were, then there are at least 2 other possible options (No$ and mGBA). This thread exist purely for my own curiosities as I have a Japanese cart in the mail. (Also, what lag does Bizhawk emulate that VBA doesn't? I've run the game on both, and haven't seen lag on either...)
Bizhawk uses the mGBA core.
no$gba has timing accuracy issues mainly. It's nice when you need the debugger, but for emulation accuracy stay on mGBA core.
A lot, if not all, of the lag skipped on VBA comes from loading the portrait sprites. I remember in my testing that VBA was gaining either one or two frames on BizHawk with each portrait change. Console was also losing multiple seconds before even gaining character control. gcah once estimated an advantage for VBA of anywhere from 30-60 seconds.
