I can't help but think that a contributing factor to that confusion about figure heights is the 'relative' nature of the scaling in the various apps. 
It seems like a small issue, because scaling a couple of content items up or down a bit so that they work together is relatively easy to do. But in a complex scene this process adds a lot of extra time. 
Also, IMO and experience, it's not always the best practice to do everything purely by eye - camera perpective can be very misleading when it comes to judging scale. Having to check everything using the front and side elevations gets tedious and can also be confusing (most times if you're using any kind of scenery prop you have to preview in wireframe mode to see into the scene and the jumble of lines can make judging a specific item difficult).
By the sounds of it most people don't even recognise that there is a discrepency between Poser and D/S measurements, and isn't a big deal anyway.
It's really only because the content available can be used in both Poser and D/S that the differences become a problem - if we all used just one of the two apps then everything would be scaled using the same measuring system and so work together. I'm not advocating that we should all either use Poser Or D/S, but that having the same scaling in both would make life a little easier for a lot of people.
In my mind it's just another annoying factor that I wish I didn't have to be distracted by in the creative process.
Ah well, it's not going to change anyway.

 

PoserPro2014(Sr4), Win7 x64, display units set to inches.

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