I would really like to try some metal kits some time.
Used to collect plastics when I was like 9 or 10. But from what I remember painting them was just horrible. Specially if you had a rather large collection. I didn't went out to buy a box of soldiers. I'd go out and buy the same box 5 times to get some quantity.
Even still, I couldn't paint them like the metals are painted. Simply too nice, weathering and all that.
No metals are simply of an outstanding quality that I could never achieve with plastics.