When using whole, wet hops (or maybe even dried for that matter), is there any disadvantage to splitting the cones in half? Is there any data available to support splitting them in the first place, such as a stronger aroma in the finished beer? I believe that the increased surface area would be preferred when dry hopping, but every picture I see of this has intact hops. For the purpose of the question, assume that they are split by latex gloved hand or with a sanitized knife and dropped directly into the kettle or fermenter less than a minute later.
There is no significant advantage to do this as far as I can see. Here is my reasoning: When you account for using pellets vs. whole hops we typically only consider it a 10% utilization gain. Pellets are completely pulverized and you only get a 10% increase. Slicing hops in half or even quarters you'd be looking at probably less than 2-5% increase, still not at pellet levels. And you'll probably lose that increase by getting the lupulin glands all over your hand, knife or scissors when you cut them up.
Not worth it.
Maybe splitting them in half won't do much good, but chopping them up into a lot smaller bits might. After all, this is why hop utilization of pellets if higher than whole hops- you are increasing the surface area amenable to the wort.
However, when I say "smaller bits" this probably does have to be quite small. If you are going to do this, you might as well use pellets unless you are particularly attached to grinding whole hops (maybe they are your homegrown hops?)
I reckon the disadvantages would be that you are going have lots of undissolved pieces of hop flower in your brew and it's a lot of work!