Okay, the most important reason for a "mesh" jacket is to hold armor in place and what really matters is the armor inserts.

You'll know how good the mesh and seams are by touching it with your hands. It's gonna be a personal choice.

A few years back I got a Poker Run mesh jacket on sale for $10. The jacket is great with packets where I like them and it's FULL two sided mesh. The armor was JUNK! Just thin pieces of foam, BUT, I was able to get CE Certified armor for elbows and shoulders from Amazon and the jacket had pockets to accommodate the full size pads.