1 Cor 2:15

Tichendorf 8th Edition reads ὁ δὲ πνευματικὸς ἀνακρίνει πάντα, αὐτὸς δὲ ὑπ’ οὐδενὸς ἀνακρίνεται. 
KJV reads "But he that is spiritual judgeth all things, yet he himself is judged of no man."
NASB reads "But he who is spiritual appraises all things yet he himself is appraised by no one."
NET reads "The one who is spiritual discerns all things, yet he himself is understood by no one." 

"He that is spiritual judges all things." is easily understood. "Yet he himself is judged by no one" is a bit hard to grasp.  Clarke's Commentary uses "convict". Barnes' Notes uses "discern". Wesley's Notes also uses "discern".

I personally liked the NET version. However, I am also convinced that using the word "judge" is still valid. Matt 7:1 specifically speaks of a person judging against other people judging him. Luke 6:37 also says the same thing. Rom 2:1 also refers to the same sense. All the three verses talks about judging others in the wrong way. Paul in 1 Cor 4:5 also says "judge nothing". Obviously, it is a different things that 1 Cor 2:15 is referring to.

Paul in 1 Cor 6:1-5 says that we "shall judge the world". Rom 16:17-18, 2 Cor 6:17, 2 Tim 3:5-6, 1 John 4:1 also refers to judging.

I am convinced that "we should judge" but we also must "judge ourselves" so that we will not be judged by others (1 Cor 11:27-31). Zech 3:7 "If you walk in my ways, and if you will keep my command, then you shall also judge my house".