The battery bit is debatable, especially since they skimped on battery capacity and batteries do wear out. These phones can go 2-4 years easy and may need a battery at some point. As for swapping out a spare, I'd rather carry a high capacity battery pack with USB and Qi charging capabilities, get 2 or 3 charges out of it instead of just one with a spare.
But the loss of the SD card is not such a big deal to me, for many reasons. First, my very first Android phone (2009?) came with something like a measly 40MB of usable app storage, when you could buy gigs of flash on a thumb drive for like $10. It was ridiculous. In my opinion the industry has stuck with 16GB as a baseline for far too long, its just not enough. Now that we actually HAVE decent options like 64GB and 128GB, with 32GB as a minimum baseline, plus so much free cloud storage, SD storage just isn't that important any more. SD is way slower than the built in storage, and all the security changes in recent Android versions have more or less screwed up your ability to use it the way you want to anyway. In my case it was a dumping ground for photos, videos, mp3's and maybe some digital content like audio and ebooks, plus offloaded apps to keep them from clogging up the stingy 16GB phone storage. I virtually NEVER actually removed the card from the phone, once it was inserted the day I bought it. Now with 128GB on my S6 and terabytes of space on Dropbox, OneDrive and Google Drive I no longer have to deal with it. Granted having an option of SD expansion might be less expensive than paying the premium for 128GB, but it would not be a better experience, or even as good.