There shouldn't be more than 1 or 2 dB difference between M50s and M60s. I guess dialog might be a tiny bit more clear on the 60s because of the midrange driver so again you might need a couple of dB extra but that's it.

Don't read too much into "having to crank up from -70 dB" -- most receivers go up to ~+10dB but very few go down to -70. I find there is a fair difference in required volume setting from one input to another... listening to FM Tuner I'm normally between -30 and -20, but listening to DVD / CD I need to crank up another 10dB to get roughly the same volume. CD "background" is around -20dB, CD/DVD "listening intently" is about -10dB and CD/DVD "cranked" is up around 0dB on the volume control.

Note that depending on what the auto-eq did to your per-speaker settings you might have another 10dB either way, ie if it turns most of your channel settings to -6dB you're going to have to crank the volume control up 6 more dB to get the same sound you had before.

I would set all the channel settings back to zero, disable the auto eq, tweak the sub's volume control until it sounds about right and use that as a starting point. I'm guessing the auto-eq got you...

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8