I agree, that
Ultra 128GB MicroSDXC is nice for the size. I'm testing one to store daily hot incremental images of a system drive (since my family members won't always be in the LAN, and it's not convenient to attach a USB drive each time). ShadowProtect showed the compressed block-level imaging process averaging just 10MB/s to this (exFAT) card, vs 100MB/s to a USB 3.0 (NTFS) HDD. So it's definitely slow, but I think manageable for incrementals. The 128GB size makes it feasible, as long as the internal drive doesn't store too much, and I restrict how many sets of images to keep.
But for some other uses I'd prefer that faster
Extreme Plus 64GB MicroSDXC. Haven't bought more though, since I'm hoping they'll have a 128GB version soon??
I remember having bought five or six of the Ultra 64GB MicroSDXC cards when they first came out, though most aren't even being used by family members...