The S7/E is only better than the Moto Z in some certain things (battery, waterproof, camera) while the moto Z is better in some other things (price, speaker, build quality, software, features) but the potential of the Mods alone just takes the Z into a whole new stratosphere, a level all by itself to be honest.. I don't see any phone competing with that (even if they don't sell)
@veteater. Actually, the Moto Z is made of steel at the back and aluminium at the sides, giving out the effect of glass. Pretty impressive stuff there.
As for me, I'd be going with the standard Moto Z. The Z and its thinness just looks downright premium (The All black one) even making the z force look at little dated when you put them side by side.
Now, for instance, If the Z costs $500, I'd easily get the black battery case ($80) taking the battery capacity to almost 5,000mah, then buy the speaker Mod (that also has 1,000 mah) ($79) and camera Mod for maybe $200 (which will also have its own in built battery) amounting to about $950 then after that, I could buy the projector and the onecompute Mod and what ever comes out down the line..
This will make me use the Z for 2+ years as nothing released next year will have any in-built component that'll be close to being as good as what the Mods will be able to offer. No phone speaker will be better than those JBL speakers, or in built cameras better than those Hasselblad ones, nor will they have projectors inside them nor will they have batteries capacities close to 5,000mah yet, (not to even talk about having all of them possible on just one device) and that's even before we start seeing all the other Mods that might be released down the line adding that the price of the modules will only become cheaper.
So, in the end, I'd rather buy a device to rule them all by spending $1,500 on the Z and modules for 2+ years, than buy a $800 phone this year and another $800 flagship phone next year that will still end up being another run of the mill basic flagship phone you see everywhere. Considering that no phone released in the near future will have the quality of those add on's natively, (except they all go modular).