Hello Michael,
Welcome back good to see you getting back into tanks
When you say 2.4 do you mean the new HL / Taigen boards or after market like the ASP or El Mod?
The HL 2.4 aren't that much different from before same sound etc just shorter aerial.
The tanks will always bounce over rocks etc as a scale object would only be about 5/10 mm for the tanks, yes heavier the tank the better, a lot of my tanks are heavy and look pretty good going over most things but will still bounce if the object is big enough.
But making them heavier comes at a price, need low ratio boxes, after market electronics etc... As more strain on the unit.
Nothing wrong with the metal tracks you had I've had Mato tracks for years and no problems with them breaking or anything.
Good you have plenty of room to drive around and have fun I would just get a tank and play and play and then if something breaks then you can upgrade that's all I did when I first got into tanks. Then you will learn about them and what you will want to do to them as time goes on or you might think its not for you and give up again.
Regarding metal tiger tank I presume your talking about the Mato all metal one, if so I would be careful with them as it's not easy to modify them, cutting, glueing removing parts etc it's a major job with plastic it's v easy. It also has the old type HL suspension which is no good, sits way to low.
Taigen put out a metal lower hull (same as the Tamiya hull ) metal insert in a plastic hull with tortion bar suspension etc, great hull you can always add extra weight (metal bar) to take the bounce out.
Hope this helps a bit
Cheers
Gra