wow.

So, Test Chamber 18. I won't spoil it for anyone, suffice after a few attempts, I took the turrets ... slower...

Wow they expect me to get up there?

Walkthrough time! :P Oh that's it, right... Fall back and swap portals, repeat.

 

Test Chamber 19.  Actually that was kind of fun.  Spoilers below.  Highlight the text to see.

And then the pysco thing tried to murder me in the fire pit.  And then goes all "I was just pretending about murdering you". Yeah sure you were GlaDOS.  And then there's still lots more game after this, it's very surprising, lots of spray paint from the previous test participants....

At this point (somewhere jumping onto ledges) I've stopped, so will finish later....

And now I'm 1.9 hours further along than last post