Giant TCR SLR2 2015 vs Giant Defy Composite 2 2013
As a general answer to this kind of question, I recommend that you buy from your local bike shop. While shops can vary, if they seem to provide reasonable service and the price is reasonable, it's worth buying from them for several reasons


the profit on your sale will help them stay in business - so they will be there when you need service.
many shops bundle clothing, shoes, helmet, bottles, lights, and such with the sale - so you end up with a better deal.
many shops will give you a free service and free adjustments - if you bought from them.


Since there will come a time when you need them, start the relationship now.