This may be a game changer for me. I had resigned myself to keeping my S4(32Gig) with a 32Gig SD card. I have pictures galore, including some video. And not a few game apps as well. So storage is a concern of mine. The S6's lack of SD made me really think. The 128 Gig version was a bit pricey, the 64 was going to be my limit.
Now it may look a bit better:
The storage issue is gone, the battery issue is pretty much gone.
Now for the size issue:
My S4 with a Caseology case measures 139 x 73 x 13 (mm)
My "other half's" S6 with case measures 149 x 78 x 13 (mm)
The IPhone 6 Plus no case measures 158 x 77 x 7.1 (mm)
The Incipio case for the S6 measures 156 x 76 x 15 (mm)
So basically, comparing Apples to Galaxies (humor intended), this new case for an S6 makes it the same height/width as an I6+, and only 2mm thicker than what I'm used to with my S4 and the S6. Height is the only big difference adding about 7mm to the S6, but that's not so bad a tradeoff for a huge battery and an SD slot.
I have big hands and carry my phone in my back pocket (lots of room there), so the 7mm is not a problem.
I can see this for travelers who are gamers and movie buffs.
I'm holding out on reviews of how users like the switch between battery and SD, but I'll keep my eye on this one...