It's not a question of which one is better. It's a question of your personal preference. UEFI is more secure, but in its default "secure boot" mode it takes longer to boot, and will not let you boot from a CD/DVD. Also I believe (but am not sure) that your hard drive has to be formatted MBR with UEFI. Of course if your hard drive is over 2 TB, you'll have to format it MBR anyway.
Good luck.