Swapping internal hard drives I have a mid-2012 MacBook Pro into which I had installed an OWC data doubler SSD (removing the optical drive).  I originally placed the SSD in the original HDD bay and moved the HDD to the data doubler bracket in the optical bay.  I would like to switch these around (HDD back to its original bay).  I'm assuming I should be able to switch the two drives around with no negative repercussions to normal operation - i.e. this should not require a reformat/reinstallation of the boot drive (which is the SSD).  Would that be correct?
I don't think that will be a problem, but you may initially need to hold the Alt key while booting and choose the Startup drive. If it still won't boot, reset PRAM with holding altcmdPR while booting.