I believe he is asking more about the diminishing returns of EE at higher levels/tiers...
A lvl 25 armor with ~75 EE would be about the same as a level 40 with 30 EE. At level 45 it would only have the equivalent of 20 ee.
I would expect that at level 50 it would only have ~5 EE.
There for at level 50 I would choose a level 50 armored with + stats over the level 25 with 75 EE.
Depending on how much +stats you have, I would consider it at level 40/45...
Just look at the defensive trade off vs the increased damage gain, and maybe test it against a few waves.
In general for solo climbs I ALWAYS suggest going for EE armored over stats.
Reference this image for the diminishing returns of EE.
/e just realized Juston was on point... Oh well, my post expands a bit more on it.
This post was edited by hasteful on Dec 8 2015 03:43pm