Try this then.
Go on Beta, roll a rad, an Elec, and a shield, using my builds.
Then roll an invul. Go to monster island agro 4 GMs see which one survives the longest.
Then run any praetorian AV arc with the mixed damage types prevalent in late game, or even some dark astoria arcs.
Tell me which one come through easiest.
Keep in mind I'm an invul player also, its very good, but there are various mechanics that allow the others to surpass it in the end.
Or if you would like to run with my SG we are a fun crazy bunch you are more than welcome to, I could show you what they are like. And please don't take this as a flame or me trying to one up you - thats not it at all, I assure you, I remember reading you back on live and always like what you had to say, I am simply looking to collaborate with you if you would have it.