Playing mostly solo, does it make a huge difference on your armor if you go mainstat vs ee? from what i can tell the demand is split down the middle, i'm just not sure i understand why.

Main stat = more damage, ee = more defense when it comes to armor. Depends on what your trying to do or the group your with is what decides whats better. If your group is all damage maybe you wanna throw on the ee armor and be a tank, vice versa.

Having solo'd a lot I recommend main stat on robe classes and ee leathers/scales on classes that can use them

this is a good idea. soloing on robe classes can still be good with salvation if you got decent heals.