1200 miles? They don't want you to change the oil for 10,000 miles or 12 months! There's an additive in the OEM oil that helps the reciprocating parts seat in properly.
Given older Hondas' reputation for burning oil, I'm inclined to follow their directions. However, when I do my first oil change next October, I'm planning on using full synthetic; I always do. It's much much better and on a year-to-year basis it's just not that much more expensive.
Congratulations on your new car and welcome to TSX Club!
Synthetic is recommended AFTER you break in the motor. I would recommend not going to synthetic until after a year or about 10,000 to 12,000 miles. If you really want to go synthetic I wouldn't go any earlier than 7500 miles.
I spent a few years working for Nissan's GTP program in the Dyno room breaking in the motors. We had all the free Mobil 1 synthetic we could want but we never broke it in with Synthetic. 1,200 miles on a street car is still breaking in.