New
#11
The difference in startup and shutdown times will be at most 1 or 2 seconds. The enhanced security feature of UEFI is mostly secure boot which will only boot an OS that has the digital signature associated with it to define it as "genuine." Those "benefits" of UEFI over legacy BIOS alone just would not make it worth it, in my opinion, to mess with upgrading the drive to GPT partitioning and UEFI booting.
Now, I have a bit of OCD. It would just bother me a little bit in the back of my mind to know my computer was UEFI capable and I was using a "compatibility mode" to turn off UEFI and be booting in legacy mode. So, only because of my minor little "disorder", which also means I don't like burned out light bulbs in my house either, I would convert the drive to GPT and UEFI booting. But I would do it manually and not use MBR2GPT. It is extremely easy to backup the OS partition (and any data partitions on the drive). Wipe the hard drive and set the blank drive to GPT. Create your own EFI System Partition. Restore the OS and data partitions. Then create the boot files in the EFI System Partition with the bcdboot command. Everything except the actual backup and restore of the OS and data partitions I can do now from memory in less than 2 minutes.