Started a second reply, because I was getting photo upload errors.
Yeast cake had different characteristics too. The soft water batch was more flocculant and chunky compared to the fine sediment of the others. It was less compact so I got one less 12oz. bottle from it. The other two batches yielded 2 bombers plus 4 x 12oz plus remnants. The remnants from all 3 yielded 2 extra blended bottles.
Tasting notes:
Soft water: clean aroma, perfect balance, no off flavors, bright hops, no astringency, spiciness from the hops, clean malt flavor, quite honestly far exceeding my expectations for any of these batches. A really nice pils worth scaling up.
Hard water: sweet aroma, rounder hop notes, a little honey flavor, balanced and melded, no flaws noticeable, upper teeth clinging and center tongue mouthfeel, maybe a slight yeast like flavor.
Boiled: sweet aroma with some yeastiness, more hop than malt in the flavor, muddled or separate malt and hop flavors, a slight grassiness, mouthfeel similar to hard water batch but less so, little phenol or rubber band character, but very little.
I was shocked at the results at this point. The order of preference (soft favorite then hard then boiled) is opposite of my expectations. I also expected the high sodium of the soft water to deter fermentation. Yes, that batch had a lower mash temp, but it attenuated just fine.
There were comments in my prior base malt experiment that water may affect color. That was confirmed by this.
I believe the flocculation improvement with soft water is noticeable.
I'll update again if there is a change after bottle conditioning.
My water is high in iron, but I wouldn't have tagged any of the flavors to that. The soft water has it almost removed compared to the others. I suspect that's the major flavor differentiator.
Happy with the clearly discernible results, even more so since it completely countered my expectations.