How would you rate the difference of honey production between the two?
The bigger the colony (numer of foraging bees) the better the honey production, so the 14 x12 will win hands down if the colony is restricted by brooding space. There is, however, likely more residual honey in the jumbo hive after harvest, unless you are prepared to extract some 14 x 12s. That does not affect me as I use them around the colonies to strengthen winter stores etc and I don't often feed any sugar. If I were in it for the maximum honey return, my outlook might be different
How would you compare the likelihood to swarm between the two?
Both will swarm. That is the naural instinct (to reproduce) or they would have been extinct long ago. Depends on the type of bee. The single area where the 14 x 12 wins hands down is of swarming caused by lack of brooding space.
How successful is overwintering between the two?
Take your pick. A full 14 x 12 will generally over-winter and expand in spring without extra supplies being added by the bekeeeper.
A single standard brood should over-winter OK, but is more likely to starve in spring due to rapid colony expansion and a dearth of forage (for any one of several reasons). A 14 x 12 is nearly equivalent to over-wintering a standard brood with a super, which was what I used to do. No problem of the bees needing to move ino the upper frames because of the gap with the jumbo - as there isn't one!
The way I look at it it is this; if the queen needs extra laying space in the springtime, I supply it. That is often a super above the 14 x 12 for a short while. If my broods were smaller than a standard brood I would not have quite such compelling reasons to have changed from standard to jumbo format.
I do not like a 'brood and a half' all season and in some ways the Dartington is as good a compromise as any - just not very movable!
Double standard brood is the one other format you have not considered here. That has the advantage of more size with lots of standard frames which are worth taking to the extractor, but only the one size frame in the brood area allowing them to be swapped around so much more efectively than with the two frame sizes of the brood and a half.
There is no ideal format. They all have upsides and downsides. Beeking is a compromise.
You just need to list all the pros and cons and your particular requirements and whittle the list down until you are happy with your choice/compromise. I think weight of boxes might be another consideration (or ease of movement of hives if you 'follow the forage') you might want to include. There may be others. My list included brood nest shape and over-wintering with OMFs, for instance.
Regards, RAB