First mission on endless mode. Just did it myself yesterday and leveled up my sorc from 45 to 100 = max quite fast. About 5 runs with 16, 20, 20, 25 and last run were 30 waves. Took about 3hrs.

cool, thanks bro

Great suggestion, thanks!

There is a map where your income is based on time rather than kills. It has 3 generators in the middle of the map. Because you can in the early levels keep an enemy alive and kite them all over the map you can get massively ahead on income and then ride that income boost to very late levels. When you do finish the map XP gain is insane.