2012 tcr advanced sl or 2014 defy advanced

On the plus side though, the change from even 9 speed to 11 speed is a revelation. When you're cycling along and wish it was just a little bit easier or you want to go  little bit faster, the close ratios of 11 speed are awesome.  I once explained it to someone as feeling like the difference between driving a manual car versus a CVT automatic, with 9 speed there's always a compromise in how hard you wand to pedal, with 11 it seems there's always the perfect ratio.

Then apologies again, I wrongly assumed you were UK based. You don't say where you live, but it is still worth checking whether dealers have offers on. As I said, most of the major manufacturers are currently releasing their 2017 models, and 2016 old stock prices are dropping as a result. Too many people in the UK don't want "last year's model".

Also, if budget is an issue bear in mind something a dealer told me a while ago. Moving to an 11 speed groupset from a 8/9 speed groupset, is like moving from a family car to a sports car in terms of running costs. The thinner, lighter, chains for example wear quicker, and if not replaced soon enough, the chain will start to eat the cassette. Now there have been plenty of threads on here about how long a chain should last, with claims ranging from 8oo miles to 3000 miles, so no need to repeat, but 1500 miles would be a reasonable average. It depends on lots of things, how often you lube, what type of lube, what type of weather, how much dust do you ride through etc. The point here being, somebody selling a bike is unlikely to have changed the chain recently, so you might want to assume a new chain and cassette in your budget. Also examine the cables for signs of wear and freedom of movement.

Tcr advanced sl is an awesome bike though I am biased as I have one.

Other posters are correct in that the geometries are different and designed for slightly different purposes. Not necessarily a problem, but in your case the fork's steerer tube (maybe even the seat post if ISP) will have already been cut so you may not be able to raise the front end, if TCR proves too low.

Also agree you should consider the various deals on new bikes online at the mo - trek, giant etc.

Ultimately if the TCR fitted you, and you're a 'press on' kind of rider who likes hills, on a strict budget, that'd be my choice, hands down. The 2012-2015 TCR's are v similar, the only big changes coming in for 2016. You won't get lighter for the price.

JL, in case you found my previous answer unhelpful (in which case I apologise), you might want to have a look at what is available in the sales at the moment. For example a brand new Emonda in 105 spec can be had for £1100, with full backup, full Trek warranty, and no doubt a proper bike fitting. With 2017 models now launched, I am sure there will be good deals from all brands including the ubiquitous Giant. To me, the bikes you quoted look expensive, and peted76's asking price for a much better Ultegra spec would support that view. And there are few things in this World as nice as a shiny new, unridden, bike.

Update: Going price for 2016 Defy Adv 2 wearing 105, £1039 - choose your dealer, full warranty, full fitting. Why buy somebody else's cast off for £100 less!

Correct me if I am wrong, but are you not comparing a full race bike with an endurance bike? Totally different geometries and in this case totally different gearing? Should you not first decide what style of bike you want based on the type of riding you want to do and then choose between different endurance or different race models as appropriate, or is your only prerequisite that the bike has Giant written on the side? (I know it is sacrilege to say this on this site, but other manufacturers are available!)

Age has little effect on carbon.

Both good bikes, pro's and cons for both..

TCR Pro's - Wheels & price. //  Defy Pro's - newer model.

Depends on the type of rider you are.. looking for a social 50miler on a weekend - go for the defy, looking to hoon it round the streets in a chain gang, go for the TCR. (Both models do both adequetly but the defy is designed for a bit more comfort and the tcr is race geometry to get you longer(?) and lower.

For what it's worth I'll be listing my 2013 TCR Compsite, full ultegra for £700 on ebay or £600 off ebay. It's a size small. (Just in case).