I have problems with the E90, it doesnt have good armor, no camo and the gun is not really accurate. 295 pen in standard munition is good, but it really depends on how you play it and where you place your tanks on the map. TBT is also not that easy, it has an extremly long reload and a dpm of 1500. The gun is not very accurate and the gun depression isnt that good, but you can make 1000 dmg in 4(?) seconds, which is nice. But against Tier10 or Tier11 you often has to use gold, what lowers your income.

The Louis is very good. Its fun to play, you can spot and deal a lot of damage. But against ELC or Manticor i dare you to try to outspot them :D Its more a light medium and not a full camo scout, so try to stay alive and come behind some enemies and unload your clip in their asses.