This sounds interesting. All of my NIK Aperture plug-ins are 32bit though. I'll try this once NIK upgrades them.
You might as well try now. Booting the Kernel in 64 bit has little to do with Nik plugins being 32bit (unless they load Kernel extensions which I very much doubt). They should work just fine, though you might not see any speed difference.
Apple has been too conservative IMO in defaulting OSX to boot in 32bit Kernel in most of their latest hardware AND making 64bit boot so arcane and undocumented. I think that too many users are missing out on possible performance enhancements because they are just not aware of this issue. Any performance enhancements would come from low level activities like I/O though i.e. things that the Kernel performs to serve the apps running.
I recommend this http://www.ahatfullofsky.comuv.com/English...ms/SMS/SMS.html
utility to show you what your particular system is capable of and to be able to easily make persistent setting about whether to boot a 32bit or 64bit Kernel (without having to go through the 6-4 keys pressing juggle every time you boot your Mac or edit OS files)