The ability to roll in place on top of someone with an explosive probe also results in near oneshots. I played this game earlier today just to pull off a bunch of explosive probe / roll combos :
Full pyro is pretty viable too. It tends to get less dps than ap because it lacks the aoe but can still do some decent numbers.
Here's a screenshot from a fairly recent game :
http://i1076.photobucket.com/albums/w446/bourk11/Screenshot_2013-06-09_14_25_48_172549_zpsb12f0520.jpg
Could have been better but enemy was dying fast
powertech dps 1457
http://i1076.photobucket.com/albums/w446/bourk11/Screenshot_2013-05-26_00_28_32_372374_zpsd51dc255.jpg
server - shadowlands
name - boris