Well worth it if implemented properly. RAID1 or better, regular backups off the array, used where I/O performance will be best realized ...
There are brackets you can find on Amazon that handle 2.5 to 3.5; the ones we get hold 2 2.5 drives in one slot. You should check to see if you have sufficient power connectors in the box.
Depending on your current config, you may need a PCI[-e] RAID card as well.
