I know of the C&C34 and an acquaintance owned one for many years. I heard nothing bad about the boat and it seemed to perform well in the Darwin to Ambon bluewater classic of 600 miles.
It is a good looking boat. But, if good looking was the qualifier for performance, every buxom blonde on the planet would be a CEO. So, there goes that particular analogy.
I am sure you have searched the internet for real appraisals of the boat. One of the great designers of our times, Robert Perry, has this to say Perry Design Review: C&C 34 + and 34R
For every person who has something good to say about a boat, there will be someone on the opposite side of the fence with tales to the contrary.
Here's a spec sheet C&C 34 sailboat specifications and details on sailboatdata.com
One thing which is worth a mention is the designer, Bruce King. This bloke doesn't design failures. He was in the business for a million years and has an excellent reputation.
I hope it turns out to be a winner for you. Please let us all know how you get on.