The R3 is a fantastic bike. It handles like nobody's business, nimble as gazelle and stable as a tank on the way down the hill. It's fairly comfortable as far as aggressive road bikes go. It's a fun bike to ride.

$3,000 is a lot of money. Nobody can predict whether you'll be happy you've spent it or not.

You should rent one, if possible, or talk to the people at some local bike shops about your thoughts. The LBS around here that's a Cervelo dealer encourages people to do all day test rides. You come in in the morning, ride 50+ miles, and take it back in the evening. Rinse and repeat. Then you can believe your experiences instead of a few strangers on the internet.