Yep.
I would double check the backup. *Should* is not a word you want to use before you reformat the drive.
I'd also backup the crucial files to a second drive. I *think* you can also just mount the time machine backup as a second drive and copy files from there.
The only reason I recommend this is to keep the various bits of the OS as pristine as possible. If you've got some old driver or something causing the slow down, you can copy the problem back inadvertently.
I would double check the backup. *Should* is not a word you want to use before you reformat the drive.
I'd also backup the crucial files to a second drive. I *think* you can also just mount the time machine backup as a second drive and copy files from there.
The only reason I recommend this is to keep the various bits of the OS as pristine as possible. If you've got some old driver or something causing the slow down, you can copy the problem back inadvertently.