I miss several things about online. Playing multiple tournaments simultaneously, the hands per hour, the availability and variety. Coming home from work and playing PLO or Stud/8 or Badugi micro ring games for a half an hour or so. 45, 90, and 180 SNGs.
However, as has also been said, live players are cartoonishly soft on average and only at a live table can I be the person with the most knowledge about range, ICM, 3-betting, short stack play, etc. etc.
Going from Online to Live is like
Flowers for Algernon, except without anyone knowing how much smarter you've become.