status-completed - we have done a bunch of work on mobile views for these pages. We dropped some features that exist in the non-mobile views (to save bandwidth, for mobile aesthetics and mobile UX).
Desperately needs phone-friendliness!
This is what my Activity page looks like on my phone (all screenshots are from Chrome on Android; first two at default zoom):
That's not very readable. (These uploaded images are large even after I shrunk the captured images; imagine on a phone.) For comparison, here's what my profile page on another site looks like:
Ah, much better -- I can read that.
The new Profile page has the same problem as the new Activity page -- it's trying to scale the whole thing to my 4.8" screen. When you rolled out the new profile I assumed that was temporary and that a mobile view would be coming, but it sounds like you're getting ready to roll this out and I don't see that yet.
Also, the layout on the reputation tab on my phone is a little wonky (but is ok in a full-size browser):
