It may not make your vaping experience better, but man does it make grinding way easier. I tend to grind up at least 2 or 3 grams at a time as a heavy user,I can do all that at one time with the bcg large and it's easy (compared to all the other grinders I've used). Feels nice, looks nice, I end up just playing with it half the time.

I would just get a regular sized one that's factory seconds, those are like 30% off cause you can't pick color and they might have a cosmetic defect, I can't even tell why mine was factory seconds tho.

https://grindersforlife.com/shop/factory-seconds/

It depends entirely on the device you're using. Higher quality grinders tend to use stronger steel metal which holds a "blade" longer so it actually cuts the herb as opposed to simply smushing/tearing the herb.

Over time the cheap grinders wear out, and the really cheap ones start flaking metal or paint into the ground up herb which you really don't want to smoke.

Additionally there are different types of grind. A fine grind is great for conduction style vaporizers (like the Pax) where the oven heats up and the heat is physically transferred through the load of herb. Fine grinds help for cloud chasing and a more thorough extraction.

For other vaporizers like convection style desktops, a loose fluffy grind like the Santa Cruz Shredder or the Brilliant Cut grinder (with a coarse or medium grind plate) help produce fluffier grinds that help enhance the vapor flavor during conduction extraction.