The answer to your question is which bike fits you better? Both frames are very good and the components are comprable. I dont know which size your looking at so I pulled the frame dimensions for a 54 cm bike and compared them here for you:

Felt Cervelo
Head Tube angle 73 72.5
Seat tube angle 76 75
Top Tube 540 557
B.B. Drop 70 60
Head Tube 100 120
Front to center 591 609
Chain stay 405 387
Stand over height 756 776

What does all this mean, that the bikes are different. The cervelo is longer from the center of the bike to the handlebars. The Felt is the same length, but is longer from the center to the back. The difference will be noticable to you on the bike.

I think you should go to a bike shop and have a professional fitting session done. Look for one that uses a power meter. They can put you into the "proper" position and then tweak it based on comfort/power.

If your not comfortable using a bike shop talk to a local pro. Living in SLO city you have a few choices. I'm drawing balnks on names but I know Robin Oswald lives there. I'm sure she can help/direct you to someone local with great knowledge.

Good Luck!

I think that's going to depend on how much of your height is in the torso vs. the legs. I'm about 6 foot with longer legs so I need a shorter top tube even though my arms are long as well (when in the aero it's mostly the torso that going to stretch across the frame of the bike), I also have a shorter stem.

Lots of factors go into getting comfortable on the bike. I second Mike's opinion on getting a fitting. At the least go and take a look at both bikes first hand (if you're looking at a deal online, see if the local shop will match it). This way they can do adjustments and setup for you, switch out seat post if need be, shorter stem, setup aero bars, etc.

Dont just get fitted to a bike then add a-bars later. That will alter your position on the bike and force you to make other changes. Defeats the purpose of having a professional fit. Check your local bike shops and see if they have a fitting cycle. Common ones are Serotta size cycle or Waterford makes one. Be honest with them and let them you your probably purchasing a bike they dont carry, but want them to work with you on the fit.

The bike-fit session is a two step process. The first is to determine which bike is best for you. As I outlined in the post above, each brand and often models within a brand are designed differently. The first step of the fit is to determine which brand /model most closely matches what your position should be.

Once the bike is purchased the second step of a fitting session takes place. This time they make the necessary adjustments to perfect the fit. The best foundation was layed with the initial numbers to get you onto the best frame for you. Now its a matter of tweaking and aligning to make everything perfect.

A quality 2 step fitting session will set you back ~$200. It seems like alot, and it is, but in the end its worth every penny. To help defray the cost try to do some negoiating with the store. Let them know you intend on buying your helmet, pedals, future tune-ups, clothing and need some lessons for on the rode maintenance. They might be willing to discount future purchases for you.