So much of what to look for in a tank depends what what you want to do with it.
I like the modeling aspect, so a plastic kit is preferred.
But, I also battle the crap out of them at Danville, just to break off all the detail I added and scrape up the hours of painting.
So, pretty much everything ausf stated above.
With all metal, the added weight puts more stress on the gear boxes during battles.
There is a lot of quick turns and changes in direction mixed in with environmental hazards.
Loose rock or even a stick can get lodged in a track and toast a gearbox.
In 3.5 years of attending, I can only remember 1 all metal tank participating in battling.
That was Troy's (RustyTrax) Taigen Tiger Late.