If you're pretty serious about having a high performance PC, then SSD's should be the goto solution currently for achieving those performance goals.
When you get to the point of using multiple ssd's in RAID, then this product becomes very interesting.
The ICY DOCK ExpressCage 4x2.5" SAS/SATA HDD Hot Swap Mobile Rack
Photo and product link credit: Newegg.com
3 5.25in bays can become 12 hot swappable SSD slots.
Here's a recent review, works good.
Yes I should be getting paid for mentioning it. :P