TLDR: mesh side panels can raise thermals. Linear flow is better than open flow.
So here's your protip:
Most agree, if you can't have balanced pressure, positive pressure is better. However do the following experiment:
Take a dryer vent tube and put a fan at the head of it to create a positive pressure situation inside the tube. Now let's pretend your GPU is at the end of that tube. Now punch that tube full of holes. The air tries to escape the soonest it can. And unless you have a negative pressure GPU (blower style) the air will likely escape before it reaches the GPU.
The same is true with mesh sides. Not only do they allow fresh air to escape but they allow for more noise. If you insist on a mesh side, make sure the side has a fan which blows fresh air below and inward on the GPU.
If you have to make a choice with what's more important to cooling effectively, always choose the GPU. They are more sensitive to heat and usually the limiting factor at higher resolutions.
In terms of cooling, chimney style is by far the best. Fresh cool air brought in from bottom. CPU radiator up top and venting.
Second best config on the list is 3 front and 1 back and 2 top with radiator up top or front. (Or 3 intake from side like loan li O11). The problem with this config is the fresh air in the lower left corner where your GPU is doesn't flow at great as rate. Air doesn't just flow straight back and then bend upward hard at the GPU. It starts curving upwards towards the exit fans almost immediately as it's the shortest path. If you are running radiators on CPU and GPU this isn't a problem.
Third best config is three side intake or front intake and then 3 top. The disadvantage in this design is the top fan and front top exhaust fan will vent before any fresh air has any chance of hitting the components. If you are running 100% radiators on GPU and CPU this isn't a problem.
Summary:
In terms of noise, side intakes (ie: loan li O11) will always produce less noise than similar front intake configuration and mesh. Avoid mesh side panels unless you have an intake fan pointed right at the GPU. It will still be noisier than a glass side panel. In terms of performance and noise, sealed Chimney configurations are superior.