I decided to go for the Pinarello for two casual reasons:
-The shop selling the Giant is local, but small and does not have all seatposts that are required for proper fit, since there are 7 sizes of them to adapt the rider in one of the 3 frame sizes.
-The second reasons comes in a good time: I called the shop that sells the Pinarellos, and the guy said they've just got a 1-month used Surprise frame in, 56cm (my size), that the guy returned cause he found out the 54 was his size. Pretty mint, but that will save me 170 bucks

I'm really anxious to get the bike, it's been more than a year that I don't seat on a road bike! Thanks everyone, I'll report about my bike ASAP!