Beat Moon Lord on expert without dropping down to Normal at any point on a fresh character, and stayed ranged the whole time. Rough is a good way to describe it, and the Solar Pillar stuff is retardo mode. Died more there than anywhere else in the game combined. The fact you almost need to have every accessory with Armored/Warding on it until you access the next tier of content at each stage is kind of a downer, and a huge money sink. Even in Beetle Armor (second best defensively) you take an assload of damage from silly shit. And since all your mods are aimed at defensive stuff, as well as mobs increased defense/hp, you end up spending a lot of time on mobs until you outgear them by a significant amount.
Some of the expert rewards are cool... but in context, you need to get certain ones or you are just boning yourself completely. You get an extra slot after WoF, sure, but since you have to keep the Worm Scarf on or everything will two shot you... sort of ends up being a wash.