I bought MAC Prep+Prime Eye from Rustan's a couple of weeks ago. Until then, I have actually been using my home-made eye primer.
Unfortunately, I wasn't blown away with how this MAC primer works. It doesn't keep my e/s from fading and after just an hour or two, I can already see my e/s creasing. Seriously, my home-made eye primer works even better than this. But I still use it because I don't want my money to go to waste. I have very oily lids and MAC apparently cannot control my oilies. :(
So will I buy it again? Definitely not! I'll probably just look for an online seller of UDPP.