p.s. regarding the 59-16 - I found it to be a "suffer tank". Once you are finished with it the reward is the WZ131, WZ132 and the Tier X 121.
All 3 are keepers in my garage.
I find the 121 is a bit of an under-appreciated sleeper tank.
Its gun does more damage than an E5 for example (faster firing and more damage per shot).. and its turret is thicker, bouncier, and faster rotating. The tank is faster too (although slower accelerating than the E5 - it accelerates almost identically to the T57). If I'm given the choice to play my 121 or my E5 in a random battle, I'll usually take the 121. Its main draw back is the crappy barrel depression.
p.s. Don't judge the line on the 59-16.. press on to the 131. If you don't like the WZ-131 and how it plays.. stop there. The tanks above it are all very similar in play style/handling.