Hi-
Just as an example, I have a 2001 F-150 Triton v8. During that year, ford decided to change from recommending a 5W-30 to a 5W-20 oil. There were no internal changes documented between those years that would constitute an oil viscocity change. Some assume that the change was directely related to corperate CAFE numbers, which provides Ford and Honda with a better EPA standing. Others argue that the change is because of issues regarding piston to cylinder clearance. This is BS.
I've been running 10W-30 (Red Line) in my 5W-20 spec'd truck for 20,000 miles with no-problems. My father has a 97 F-150 with the same engine..he's been running 10W-30 and the engine now has 200,000 miles on it with full compression for each cylinder (he's been using Mobil 1 synthetic).
Honestly, teh choice is yours, but Honda cannot void your warranty due to oil viscocity, so don't worry about it. Just use what makes you feel comfortable.