After completing the Get M8A1! game achievement (man that was a ton of grinding) I finally got my M8A1, and it was worth the effort. So here are a couple of battles with it.
The M8A1 packs a 75mm howitzer gun which supports armor piercing high explosive ballistic capped shells, it's very maneuverable (too much at times), it has an armor of paper-like qualities, and if played right (not to be confused with the way I play it in this video) it can stack up lots of kills quite easily.
The tank also mounts a pretty powerful 12mm MG on the turret, which for some odd reason I wasn't able to fire during battles even though it worked just fine in tank test drive.
For arcade battles, the M8A1 has a battle tier of 2.0 at rank one, which means most of the times you'll get to play with bottom tier tanks (happy times).
Enjoy!