I am favoring the smaller coils. The delema here though is there are layers of top soil added over old farm land in some of the parks so there are deeper targets that are often on the fringe. But again if the ground phase is too high then the larger coils perform with less depth and tend to smother out. Largest coils I use now is the Superfly and 10x12 for those areas. Finding the 10x12 can be a happier compromize.
Recently with the Apex I have been doing very well with the stock coil landing a few nice rings and a couple nice old coins. A major part of that success was the coil has a nice balance of depth and coverage with a pretty narrow footprint so separating and isolating targets is much easier. I debated on getting an ultimate 9" for it but leaning to the Ripper instead for those extra trashy areas where the good stuff hides
For now I'm holding off and hoping Garrett makes a small concentric for it.
Monty you should try one of the carbon shafts for the Apex from Steve G., they shave off a bit of weight and the machine is really nice to swing. I think it balances much better than the stock shaft.