I took a drill and small drill bit and drilled holes very close together around the edge of the diamond shaped holes that were blocked off. I then took a utility knife and cut just the solid part out of the honeycomb part of the grill that is in front of the intake snorkel. You would have to be up close and looking for it to tell any difference in the grill from the left to the right. Could debris get in through the holes....possibly but it wouldn't be anything larger than an insect as the holes aren't very big. You can get filter covers that will keep debris from getting into the filter pleats and also shed any water that may come in as well. I don't know if it helps with power or not.....but I am very sure that my intake air temperature went down about 3 degrees. It always ran 6-7 degrees higher than outside air temperature before at speed, it now runs consistently 3-4 degrees higher. I can't tell any seat of the pants gain , but IMO it can't hurt.
Generally, more air = more power (especially colder air). It definitely can't hurt, unless there's turbulence being created from this. Probably something so minute that we'll never realize or feel.
JLT is what I got.....you are right you don't have to use one but from using them in the past they will keep your filter much cleaner.
It's injection molded so price comes from material volume. Costs would have been lower to have them open (less material per part), but that might have brought down emissions due to poor aero.
