Thanks for the replies. Perhaps I need to add a bit more background...

Practice - I've got 65,000 bike miles under my belt and I occasionally get the heebie jeebies on hills I've been down hundreds of times. I've hit 50 mph several times in the past, including on our tandem. Like I said, it's irrational.

Relax and enjoy the ride - I wish I could. The feeling I get is something like going over the first climb on a roller coaster and all you can do is hang on. It's not that bad, but something like that.

Smoother lines on corners - Actually, it's worse when I'm going down a long, straight hill.

Apply the brakes - That's what I do, but I do a lot of group rides and it sucks to work hard on the climb only to see the pack cruise away on the way down.

I suspect the twitchiness of my old bike was due to headset and wheel bearing wear. With any luck, it will work it's way out as I get used to the new bike, but I thought I'd seek some advice in the mean time.

-murray