I dunno. Those "seriously distracted" moments seem to happen often. I tend to look for those moments for anyone as a sniper. Generally, unless other snipers are aware of my location, I just won't show up there for a bit. Retreat/relocate until you've moved on, then appear again and kill you. I just don't see what a Heavy can truly do against a good sniper. Not trying to start an argument, but I would like to know what you do. Maybe it'd make heavy more interesting for me.
It completely depends on what the heavy actually gets to see what I'll do when the time comes. I'll likely just stick to sniper, pyro, or scout. :x