Especially filtering SIZES of products; I'd like to be able to find atomizers the same diameter as my mods. Or DRIP TIPS! I'm tired of browsing thousands of them and clicking on one I like just to realize it was too small or too large. Browsing huge categories can be a real pain. Thank you!

Agreed.
The whole search system needs a bit of work IMO.
Clear discontinued so I dont get pages of crap I cant order anyway, remove from search instead of only search for example I want to see all mech mods except 26650 so I want to remove 26650 from the search.
Checkboxes for search so if I wanted to see both Samsung and LG batteries in the same search I could select both but I cant because its one or the other.
Filter by availability like in stock or ships next day.

Yes yes 1000 times yes. Hope you're reading this FT!

Something as simple as a minus sign to exclude, such as:
joyetech vtwo -mini
vaporesso -tank

How about other switches, like OR:
vaporesso OR smok clearomizer OR tank

Ebay allows advanced search features.
Amazon does not.
Ebay used to allow wildcards. That was very helpful, such as:
drip tip*
^would search tip, tips, and anything else beginning with tip.