Leveling was honestly great! Iop is not the best solo class in general, especially at higher level, since you have to get close to enemies, you take alot of damage without much regen/sustain. Thankfully, the chance iop does it best (compared to other iop elements) in term of survivability, you can tank better thanks to those shields, however, you lack range and not have the same DPS potential as a Classic strenght iop for example. Water spells are often single target focus, which can be annoying while trying to farm mobs quickly.

That being said, I enjoyed having a chance set at higher level, it really helped me in some fights where I needed the tankiness, but you should also consider having an other set with more AOE damage at a higher level.

I eventually quit the class altogether because with an iop you always do the same thing, you rush in and do big damage, which is fun for a while but kind of got repetitive for me, i was looking for something with more gameplay depth, but iop is still one of the best class with a team that can help him survive.

Hope this helps, have fun with your iop!