out of the box the mini-t's are really fun.
they suffer from crappy stearing servo... im on my like 5th now. they are propritary so to replace it you have to go with an all new ESC and reciver. so a $15 servo is $100 upgrade

so i buy $12 stock replacements.
With mild motor upgrade and 6 cell pack (my stock motor lasted about...40 packs or so) is about all you need for some serious butt kickn fun! goes just fast enough that you can still control it, enough power to power out of the dips, but not heavy or fast enough to really break stuff every time you slam into something.
my RC18T is a diffrent animal. the 4wd makes a huge diff off road in hardpack, but its so fun to pull the drifts and slides you can with the mini-t. The minipins dont last long, but once you wear them down they make great slicks for the pavement.
The 1/18 scale track would be fun, but seems like you build most of it by hand, at my old house i had a nice little track setup in the back yard of nothing but hard pack dirt the dogs created for me. A few bomb holes and 1 or 2 plywood jumps (usually not more than 2" tall) and your looking at hrs of fun. (in 20 min increments)
I would like a larger track for my buggy and t-max, but like anything else, seems theres always some other project. I usually just bust it out when im in the middle of some other project and create in impromptu track (like out of the pool dig project.