Like Edge said, that's a large risk on an unknown for yourself. I would also try it out for one month before you make a larger sub for the discount. After my first month I signed up for the 6 month when it was on special for $60.00. I was hesitant, but it's looking like it will be worth it.
After getting burned with WoW's AP, I will never amke such a large commitment unless it is a lifetime memebership like LotRO had. Still kicking myself for missing out on that.