Trapdoors give too less as compared to doors, this is a really unrealistic crafting comparing earlier versions (1.7.4 and lower)
Explaination:
In 1.7.4 and below:
6 wood/iron = 2 doorblocks = 1 door or 2 trapdoors
In the 1.8 snapshots:
6 wood/iron = 6 doorblocks = 3 doors
6 wood = 2 doorblocks = 2 trapdoors
4 iron = 1 doorblock = 1 trapdoor
Do you see what is wrong? If not then this is what is wrong:
A wooden or iron door cost first 6 planks or iron and gave 1 door(=2 doorblocks) or 2 trapdoors(=2 doorblocks aswell)
Now a wooden or iron door cost 6 planks or iron and gives 3 doors(=6 doorblocks) or 2 trapdoors(=2 doorblocks)
A good fix for this would be:
Crafting: 6 wood/iron = 3 doors(=6 doorblocks) or 6 trapdoors(=6 doorblocks aswell). Please remember with this: iron trapdoors cost 4 iron so it would give 4 trapdoors(=4 doorblocks)

It is a quite unfair contradistinction. I explain it aswell with pictures.

Note: Because this can look like a new feature instaid of a bug, it is really a bug. It reminds me of: https://bugs.mojang.com/browse/MC-29510 . It is a same kind of bug.