I'm still showing 11 hours on Steam, which is odd, I know I'm at 13 at least.
Just left Shanghai, or at least left any unfinished/undiscovered quests behind (don't think I missed one. The time I missed the cholo I accidentally moved forward.) I could never be as patient as Jerykk - I like getting into danger too much. The relative safety gets tedious for me after a bit, and I don't think I've missed much at all - I still find stuff everywhere.
I do have 8 praxis' right now, though, and little interest in using them. I am not too keen on the manual ones, and nothing really seems necessary beyond more space, heavier lifting and higher hacking levels. I get that you couldn't be more advanced than JC, but the augs just seem less useful as a whole. Not really caring, given how much I'm enjoying this game.
For the first boss I kept running backwards while shooting him with a shotgun, picking up a fire extinguisher and throwing it at his face, running around a corner and dying (once because I opened an ammo box and couldn't move.) Then I noticed there were gas canisters behind the fire extinguisher. First time I noticed that I killed him - he kept firing where I was while I kept throwing gas and barrels at him. The whole fight was less than 20 seconds.