I love billboard objects, lol. So much nostolgia!
Eh, not as much as you’d think, a single thousand polygon model is about as costly as a single billboard as far as much be concerned. Where billboards come in handy is when you can render many many many of them in a single batch (like grass). MC rendering an ‘item’ as a billboard is actually more costly in many ways than 3d models, lol. ^.^;