So far, I miss...
All our old achievements, and how to continue monitoring them,
A way to filter reviews by trusted reviewers,
Being able to see Likes and Dislikes of OUR reviews, not the ones we've given out,
A way to quickly edit our own reviews after posting (caught a typo),
(Not sure if we SHOULD be able to 'Like' our own reviews??),
The simplicity of the old scorebook on the PC (entering scores requires clicking in the cell, where I used to be able to use arrows, tabs, enter, etc; the list of courses used to be alphabetical, so 371 played courses was easily navigated; mileage, holes played, etc. used to be updated immediately; dcgr player rating dropped 200 points...),
We used to be able to rejoin a forum discussion thread where we left off, not sure how to do that now,
...but then again, I'm an old curmudgeon who has been frustrated by 'newfangled tech' every step of the way since I bought my first PC in 1983...