Contender 15K "Armor gambit"

I randomly discovered this setup when trying to make something with a really fast reload. This thingy is meant to support and snipe rather than brawl. The main strengths of this TD are really strong gun (downtiered), high mobility, a drone, high RM (2), and hull aim. A side feature is the surprising CE protection this tank has.
The build sacrifices proper armor and ammo load (max. 13 rounds for 2A73) for the things mentioned above. The gameplay of this tank is a bit challenging as it relies on flanking/camping, but the drone function allows you to play on smaller maps too and support brawlers. (Or just use it for rushing, who cares)

The turret also allows you to switch the guns based on your preference. If you're a fan of more conventional guns, you can use them freely, you will get about 5s of reload for the 120-125mm. But be aware the ammo storage is very limited, so make every shot count.