You know your build is solid when...

[Uun]

you AFK in mission for 20 minutes to pick up your daughter and come back to find a bunch of lvl 54 Nemesis beating on you (including a Warhulk) and your health bar is full (MA/Inv scrapper). 

[Doomguide2005]

     Or start hopping into a series of mobs 'solo', those 7 teammates are nowhere to be found,  knowing each one likely contains an AV without even thinking about tabbing through to find which AV, where it is or what other surprises might be within and finally realizing you've just found the one with Black Scorpion ... and just start clawing away.