I think the issue is that while the mog slips are great, they slow down the act of changing jobs even more. for jobs that i store more then just empy armor for example, i need to find which slips i need (usually the less played jobs so i cant memorize which slips they require) and then make a trip which is generally out of the way and begin trading + finding the armor. id say the difference between a job that only has emp armor stored and one that stores other stuff as well like af1/relic is at least 3-5min(depending how scattered in slips the armors are...tho take note that compared to others i seem to do this fast in my experience) and that is just at porter moogle.

Only things i can see to improving this system is simply allow your MH moogle to do the trading and if possible remove the dialog after every item you select, instead allow you to select every item and then confirm the selection. I feel the delay with the chat dialog after every item and the side trip to the added moogle are the best ways of improving the time wasted w/o overhauling much.