I use to use the Calibration tone on my TagAV32R to set channel levels but Id could only ever listen to movies at -10 and this IMO was equal to the level at the cinema. So the processor or DVD/AMP is gaining 10db somewhere,dont ask me where. So when AOTC arrived I decided to try the THX optimiser and set the AV32R volume to 0db and dropped all the channels on the calibration screen untill they reached 75db on the SPL meter. Now when I watch a movie I set the volume to 0db and it seems about right.
As to bass levels on AOTC I thought they were on the low side. A good scene to test this is in the areana. The first time I watched it at 0db the spider creature hardly made any bass sounds at all. As it strikes the floor there was vertually no bass. Turn the LFE channel up 5db and the thumps on the ground come through clearly. The only thing is every flyby from a ship comes across as completly over the top.
So I dont think you should take the THX optimiser or the calibration tone on your equipment as the word of god as the amalgimation of all your equipment will show you otherwise. Instead use it as base from which to start your final tweaks, and I
think that is all down to personal preference.