Helpful tool for deciding your future
 

http://ccwf.cc.utexas.edu/~nhart/Status_calculator.htm

I just found this today... the results are pretty shocking as some mixes that I would have never even thought of become absolute beasts in the long run. Maybe if you want to know what you are heading up to check this out. If you are planning o trying out weird subs this can help a lot.

-EDIT-

(an example of a mix that can become a pure beast is a PLD/DRK or DRK/PLD... either way they are very well off all around)

Re: Helpful tool for deciding your future
 

Stat wise PLD/DRK may be good but it is a useless combination. Can't hold hate, not enough good magic spells, not enough mp. You don't have provoke, the only thing you could possibly rely on is just White Magic.

Re: Helpful tool for deciding your future
 

Yep, you are correct... one story that this site doesn't tell is the move set you will be having. That realy just depends on what a person wants out of there sub though. Do you want it to make your main class stronger, or to add moves that will make you a better fighter, or a nice mix of both.

An example of subbing just to enhance main stats is taking Summoner as a sub... it's a very dumb idea move wise, but it gives an extreme boost in MP. :p