I have a 2012 and was contemplating trading it in for a 2014 but, I've decided not too, the drawbacks to a 2014 outweigh the benefits, IMO.
If I were planning to keep it stock (which I am not but, if I were):
6.4L!!!!!!! (if there were no changes other than the 6.4L, I'd trade mine in!!!)
central axle disconnect on the front axle (introducing weakness to save 1mpg=dumb!!! This was actually my breaking point where I decided I will keep my 2012)
what we have seen to be rather finicky in other engines thus far MDS
Radius arm style front suspension
coil sprung rear suspension
^Just this list has two drawbacks vs one benefit.
Now since I want to modify mine with a lift for bigger tires and more ground clearance, we'll start a new list of Drawbacks:
radius arm style front suspension- only one available at present that I know of
coil sprung rear suspension- no lift kit available at present (though shouldn't be long before they become available since the design is VERY similar to 1500 rear)
BUT, I don't just want a "lift kit" I want a "suspension system" that gives me more travel and better ride quality than stock.
Front- as with a "lift kit" only one is available, the same one I listed as a "lift kit" (Pure Performance is the first, I think)
Front suspension MIGHT be a benefit since I think the new radius arms are longer than the old control arm setup BUT, we've yet to see if articulation is more or less in the new than in the old. Carli's top end kit is a radius arm type setup but it is VASTLY different from the stock radius arm setup the new trucks are getting. IMO the new front end is a wash, neither benefit nor drawback whether keeping it stock or modifying it.
Rear- none yet (that I know of), and when they do come out, you can bet they are going to cost an arm and a leg to get the kind of performance you can enjoy from the current leaves!
^(I am going with Carli parts (Deaver rear springs and King 2.5 shocks) and Thuren parts (shackles) and I anticipate a great ride, great articulation, and plenty of load capacity) To get the equivalent with a coil sprung rearend, you would have to go long arm (AFAIK it remains to be seen whether long arm mounts will work with the gas tank or not) and would have to revise the shock mounts as it would appear that a large body shock will have a hard time fitting into the new rearend design) My rear suspension is going to cost about $2200, expect to pay a LOT more to get similar performance out of the new rearend!!! Also, in addition to the expense, there's going to be a good sized waiting time as companies get trucks and start doing R&D! So, rear suspension is a drawback for modifying the truck. (Disclaimer: yes, I am SURE that someone will come out with a rear suspension redesign that will blow the leaf sprung rearend out of the water performance wise BUT, I am sure that the price tag will be INSANELY high on that system!!!)
^ so, now (for my intended use), the drawbacks outweigh the benefits 3 to 1!
An additional drawback for you in the case of a 2013 vs a 2014 is that the 2014 is going to cost more!
If you plan on keeping it stock, it's almost a wash but, it just depends on what's more important:
2014= bigger engine!
2013= stronger front axle, no MDS, cheaper price
If you plan on modifying it, I'd say 2013 wins!
2014= bigger engine!
2013= stronger front axle, no MDS, cheaper price, better rear suspension performance for less money (unless someone introduces a completely SICK rear suspension system for not much money which I highly doubt will happen)
It all comes down to how bad you want a 6.4L!!! I personally am just planning to swap in a 6.4L whenever my 5.7L craps out! (likely more than a decade from now, LOL!)