So I am currently riding a Giant escape 2 and is looking for a decent entry level road bike for longer rides. My budget is around $600~$700 and I am currently looking at either a new 2015 Giant Defy 5 @ $620, or a used 2013 Giant Defy 1 (2013 Giant Defy 1 size M/L) for $700. I am going to LBS to try some others too (Trek 1.1) but I prefer Giant because it's more comfortable? Is used defy 1 a good deal? I usually prefer new bike because of initial support from LBS and warranty, but Defy 1 seems to be a much better bike than Defy 5.

Without seeing the used bike it is hard for anybody to say if it is a good deal or not. It all depends upon the condition.
I tend to agree with you about buying the first bike from a shop though. They can set you up and fit your properly, which matters.
The Giant and the Trek are both good places to start. My recomendation would be to go new if possible and ask a ton of questions.

If you have an REI near you they are having their yearly clearance sale and all bikes are on sale. The biggest discount is on their house brand Novara, which are good bikes for the money. The Novara Strada and Trenta are really good bikes with great components.

The Defy 1's a very good deal if it's your size.

Giant offers good value for the money. If you live near a Performancebike, they may also have bikes on sale; Fuji bikes also offer good value for the money. I second the recommendation for REI sale bikes. The Novara brand bikes are decent quality.

That Giant in CL looks like it is in great condition and would be a good deal.

Here's the big difference between entry level Giant and Trek frames: you pay a little more for one fewer letter on the down tube.

Thank you everyone for the feedback. I am going to check out the defy 1 tomorrow or Monday and hopefully get it if it's in good condition. Seems to make more sense to get a better bike for almost the same amount of money as the new defy 5 (after tax).

Well if this helps, I am currently selling my 2014 CAAD 10 105. Its a great step up bike and its basically new no scratches, just a half season of riding, and im selling it in your price range. Other than that I would say go Fuji over Giant really.

Seems like a good offer OP.

I like the Specialized Allez. You can get deals on the 2014 MY's.

OP's looking to get an endurance style bike. The Allez and CAAD 10 are both far from this! Stick to the Giant, or take a look at other brand's comparable models: Fuji Sportif, Felt Z, Specialized Secteur, etc.

You don't need an endurance fit bike for all day comfort. OP never said endurance they just said comfort. I know plenty of guys who ride 100 miles on a "race" bike. Endurance bikes are made for shock absorption from rough roads as their Primary purpose

I do full centuries at least once a month on my Altamira, and I agree a crit-racer can be adequate for a full day in the saddle if fitted properly. But I fit bikes as apart of my living, and endurance bikes are NOT just shock absorption. They're a different approach on geometry, and many have extra shock absorption.

The OP is new to a road bike, (coming from a hybrid). There's a reason most companies make their <$1k bikes in an endurance style than a race style. It has a far broader range of acceptable fitting, which is a far better choice for people new to riding in drop-bars. Even if they get a professional fitting.

this is a pretty good time to shop for a new bike - lots of model year-end deals. I got a pretty good discount on a Giant Defy Composite 2 at my lbs - you might get a similar deal on one of the aluminum models.

Went to check out the bike today and it was in good condition. The owner was willing to do $650 so took it home on the spot. Did a quick 5 miles ride and all seem well. Thank you everyone for the suggestions an offers. Hopefully I can enjoy this for a long time as well as learning more bike tuning.

Congrats! Enjoy it in good health. I have the same model.