My Sandisk Extreme Plus 64gb is twice as fast as my 128gb MicroSDXC. While it's nice to have the space, one does get used to faster speeds than the current 128gb has.
Yes, 64 GB vs 128 GB is the difference in the benchmarks shown. Definitely a trade-off. The extra storage is good for \Dcuments like those associated with Office, photos, and .pdf, since such files are generally used by clients which roll the files into RAM, not slaving a drive.