Infraction: 10. Do not respond to terrible posts.
Message to User:
If the answer is use a sim, then your action should have been to report not reply.
... no one can absolutely answer which is better Arcane or Fire...
So, to sum up my question, what spec is better for DPS these days, Fire, or Arcane?
You answered your own question. There are two ways to answer it for yourself: try it out in game, or use Rawr.mage to simulate the various fights against the two specs. If you use the gear that you have available to do the comparison, you will soon know which spec might be better for you. Then it is up to you to learn to play that spec to its fullest.