I've been snowboarding in Heavenly since the epic winter of 2003, and I have come to love the mountain. It's huge, and the way the lifts and runs are laid out, you always find an area that is uncrowded, even on the worst day (President's Day Saturday, no doubt).
Heavenly has done a good job at adding new terrain, too. They'll look at what locals use and make it an official trail after a while - I much prefer that to the artificial layouts of other resorts.
I found that what other reviewers mention is largely very accurate: apres ski is fantastic, public transportation is free and quick, the views are magnificent.
On the negative side, lift lines can be downright atrocious (my worst wait without stoppage was 45 minutes on Sky Express), the food is atrocious and overpriced (I ended up opting for protein bars instead), and worst of all: the weekends bring lots of people that don't improve your enjoyment of the mountain: lots of rude, intoxicated (alcohol and dope alike) dudes shooting down the mountain, while hordes of beginners sit in rows blocking the runs.
The one thing I quite don't get is why so many reviewers complain about the track from CA to NV: sure, the first few times it's a long haul, but once you understand it, you can float down almost to the far end if there is nobody blocking you. Methinks some people just gave up after the first few times.
All in all, I've tried every major resort in Tahoe, and Heavenly is still my favorite: it's far bigger than anything else (despite what reviewers here say), it's much more fun when you are not on the mountain, and the mountain itself has lots of nooks and crannies you have to discover for yourself.