at the end of tbc, i used enhsim frequently, but when it came to wotlk, i got tired of simming every piece of gear.
i know an enhance fella on my realm who buyed wodins lucky neglace for >10k just for a ~7-10dps upgrade.
at some point, i just lose the interest to continue tuning my gear.
-know your exp/hit caps, haste/ap after that ( matter of preferrence ) and with high ilvl gear start worrying over crit-cap
-know your priority list
-know what gear you want to have
-give your best and have fun raiding
and fuck the rest
works out for me.