Well, neither of those have side panel windows - that said, side panel windows are nice for doing regular inspections for dust build-up and spinning fans. As for grills, not sure what you mean but generally they suggest air intake vents and IMO vent are better than doors that cover vents.
I have done several builds with Lian Li cases and frankly, I was not that impressed - especially after all the hype about them. The aluminum actually made the cases feel flimsy and felt like the entire case could induce twisting torque on the motherboard when you have to lug the system about - like outside for cleaning. Yes, that aluminum is lighter but once you fill the case up with the motherboard, RAM, PSU, heatsink, drives, etc. they are no longer "ridiculously" light. A good, solid steel case is heavier, but not flimsy. And I think that is important to keep undue stress off the motherboard mounting point as the case stays "true" with no twisting torque issues.
And the HDD cages were incredibly modular.
Modular? I say more parts to hassle with. And they add weight to the case. Drive bays can be nice, but I think the tool-less rail mounts used in those Antecs and similar cases, like the 330r, are just as easy, if not easier. The rails just fit in the drive screw holes then you simply slide the drives in rail grooves until they click and lock in place. Piece of cake.
You did not say which Lian Li but note the
PC-8E weighs 6.5Kg (14.33lb). The larger Antec Eleven Hundred V2 weighs 15.3lbs. I suspect that is due in part to the drive cages. So there really is not any significant difference and you get a sturdier case with the Antec.
Something else to consider is the location of the power and reset button and USB ports. If your case will sit on or near the floor, you will want the power buttons and ports up top. I note that Lian Li case has them in the middle.