Even though I plan using this hand held most of the time, with standard and wide angle lenses, having MLU for those occasions where I will use a tripod is a plus. I noticed that KEH doesn't indicate if the 67 and 67 II bodies they offer have MLU or not, so yes, one would presume they all have this feature.
There's another good reason for choosing a body with MLU. My local Pentax tech tells me that there were other, internal, changes to the 6x7 at the same time, and that you can basically forget having a 6x7 without MLU properly serviced today. The parts just aren't available. The newer version, with MLU, has the internal workings that were carried forward until sufficiently recently that parts can still be had.
Well,you do need ML if you want sharp exposures in the critical band , which on this camera,would be in the 1/60 to 1second range. Or even faster speeds if you use longer than normal lenses.
And "save the battery"? - the battery is essential because it holds the magnet for the second curtain open when you use MLU.
I refer only to 1st generation models,of which I have extensive experience.
If you are into long exposures (many minutes,hours) look elsewhere, or learn the " Lock open on B,and use your hat"technique, which places no demand on the battery.