In my opinion the current loadout system in Halo 4 does not enhance the pleasure in the gameplay. However this does not mean that loadouts in general are a bad idea.
They do not work in my opinion because:
Nobody starts equally, everyone has a certain gameplay advantage over others. When the other gameplay mechanics (such as ordinance drops) are not perfectly balanced this will create an imbalance in the game which will eventually lead to chaotic gameplay. Which is not that fun, since skill is not really required.
Last year a teacher told me at school that there has been a study which proved that when there is more choice, it will not always lead to more satisfaction. He gave the example of Heinz, it has a lot of ketchup flavors: spicy, classic etc. But when certain customers chose 1 flavor, they could not help but wondering ‘did I make the right choice, because there are so many other choices. Perhaps there is something better’.
Personally I feel the same way in Halo 4. I have the feeling that I always could chose something else and everything had it’s ups and downs. Therefore everything just feels unbalanced right now. Of course I would prefer a greater variety of playlists, but that is something else, since it does not had to do anything with the gameplay.
I think it would be better if there were standard loadouts, or they would at least be within a certain category, and do not add any randomness and chaos to the gameplay. If armor abilities and power boosts came in ordinance drops it would also be better in my opinion.
Other you could perhaps for objective game modes have certain loadouts that benefits your whole team. The only team based armor ability now is regeneration field.
These are just some thoughts I wanted to share. If you do not agree that is always fine;) What do you think?