If you do get a card, get the asus one ocuk sell - not the startech one.
Startech one gave me loads of hassle - hangs connecting to my c300 ssd, and driver issues (says it doesn't need one, but windows 7 moans about it).
Asus one no problem - works fine, good speed - no driver issues and you get USB3 included in the cost.
Depends if you want to upgrade to an all singing all dancing MB really. wouldn't hurt to have sata 3 and usb 3 on board.. but i doubt you will have any real use for USB 3 yet.. and there are only a few sata 3 SSD's out and they are expensive. So for the cost of £30 for the controller card it seems more sensible.
Also you need to stick the card in one of the faster PCIE slots (so if you have a sli or crossfire system it could be a problem) or theres no point in one really. My SSD read speed went up about 80mbs in a pcie x16 slot - for a total read speed of 320mbs on the c300 so im happy - but i dont use sli/cfx.