This is a tip for anyone who wants to get to the Smasher(and hasn't figured this out).
Do a bullet build first, as a Basic Tank. If you go for a rammer build from the start, you won't be able to destroy as many Polygons as quickly as a bullet build. And you'll have to upgrade Health stats, which only helps you survive, not gain XP. When you get to Level 30 and upgrade to the Smasher, you will get back all your skill points, so you can put them in the stats that you want out of Health Regen, Max Health, Body Damage and Movement Speed. Just remember to wait until Level 30 and not upgrade to any Level 15 Tier 2 tanks.
This is only a tip for people who don't do this and haven't seen it before.