Sure I also have HDD's still,, hell I am actually making a VM nas etc just for fun and using them for that....but I also know that if I would get serious with that stuff you would not stick with HDD's, you would get SSD's, faster and they use less power, it just makes much more sense for the enviroment, but also my problem is not with the harddrive bays (despite them taking up too much space if you are going for ssd's), its with the 5.25 inch bays, the CD Rom drives bays, who still has any use for that let alone 3 of the dang things....
EDIT, ah I see now, my bad, I typed 3.25 inch when I meant 5.25 inch lol