Does anyone know what happens to the tower level when you switch between tower types? For example, if you have a level 3 arrow tower and switch to a magic tower, is that tower also at level 3 or does it drop back down to level 1? I wanted to find this out before switching my tower type. I did discover that apparently switching tower types always costs 140,000 gold even if you are returning to a special tower type you had before.
I don't know what everyone else is experiencing, but I am often attacked by heroes alone that are powered up over experience level 100 and even sometimes over level 115. My main heroes are still in the 70's. Leveled up arrow towers would help a bit.