[epmatsw]

I assume the argument is going to be that on mobile the parsing time for 7kb of JS vs 45kb of JS is going to be significant.

[mhd]

And you might be able to avoid simultaneous client- and server-side rendering and all the horrors this brings with it in the first place.

[tracker1]

Frankly, everyone I know insisting on isomorphic rendering is doing it for SEO not for improved first display on mobile. Not that it isn't worth it... what WalmartLabs has done is incredibly impressive in this space.