I generally only like the large minis, which tend to have ok paint jobs, due to size.
I also love the "clear" minis, brillaint for ghosts, elementals etc which is simply not possible in metal.
However, I don't have to worry about painting or breaking them, nor carrying the ton weight metal minis are!
IMHO, the various animals, elementals, lot of the giants, elementals, ghosts, most of the dragons and large+ planar creatures are all perfectly fine on the table.
A few of the human/oid ones are ok for characters.
Nice ot be able ot put 20+ kobolds in a plastic tub, of about 6 or 7 different types, for when you play Keep on the Shadowfell
(I seperate all the human-sized ones into plastic tubs of type: human-armoured, human-light amrour; goblin; kobold etc, so it's handy to plonk 'em down on the game board).
I may add magnets to their base to add a little stability/weight, and use a magnetic grid board.