After a bit of frustration with going from dual wield to 2h with my Whirlwind weapon, I decided to try out Slam again, and found it...rather effective. Instead of the painful 3.6 second weapon swings, Slam's only got a 1.5 second cast, leading to much faster hits.
It does get pushed back by melee damage which is a bit annoying, but even with pushback, Slam is still faster than a 3.6 melee swing. In general, I'm finding Slam to be much better than Heroic Strike.
Is it good to use Slam like this while soloing? And is Improved Slam worth it too?