"How did it affect the handling? "

It sucks, so don't do it. I tried it. But do, get a neutral seat post and put the seat forward. This will give you around 76 degree multi-sport position. Now add small size Syntace C2 aero bars and you're in business and can now go out and do your Team ONCE/Luke Bell/LVL imitation.

Giant TCR/OCR compact frame geometry lends itself very well to a 75/76 "multi-sport" position. If you go to far forward 77-79 on a forward seat post the handling is effected in a negative way.

I use my giant with a thomson forward post with profile carbon X's. Not ideal I know going by the general opinion but stability is fine once you get used to it. I won't change anytime soon. The stiffness, comfort, and power transfer gains are more than owrth it. Just make sure you have clearance to the bars with your knees (mind you I'm 6'3 and I fit fine on a large).

Get a pair of Spinachi and that's all you should do. Forward set posts handle like ass and are dangerous. The most you should do is a neutral seat post.

if you don't mind...as a side question...i was in my LBS looking at the beautiful giant tcr composite...and loved the handlebar tape...the guy didn't know offhand who made the tape....does anyone know???? the tape was not cork....it felt a bit squishy and rubbery....maybe a gel???? i really liked it....it seems like it would clean up good too....any ideas what type of tape this would be on the tcr composite?????...thanks