The rep system could define for example a scammer from a high quality member.
Yet, the community abused the rep system and rep'd randomly, and some would get rep fucked
because of 1 post. In my opinion it should be brought back as long as it has
some kind of restriction to it. (e.g: one can only rep another if the account is at least x old --
an IP cannot rep an account with the same IP, and what not)
Also, lots of members would abuse the Tutorial board, making something that some of us don't know,
but, as soon as the rep system went down, the tutorial board is pretty dead.

So, in general, you should bring it back.