The whole jumping between defunct test chambers thing is awfully confusing.
You should also play test these more, there are a lot of places to get stuck, or writhe with inconsistency. For example the first jump can be done a number of different ways and can be hard to get right even if you do it the same way multiple times; it needs a much greater tolerance. near the end of one test chamber, you're supposed to portal through a grate onto a tilted panel, and then peek through the gap it creates to portal across a room. However, the portalable surface across the room is almost too dark to see, so I crouched and just dropped into it. Never forget about crouching. just wound up in a room with missing surfaces on the floor... No choice but to start over. I do admire your use of the hammer editor, but only if you're using it to your advantage over the standard editor, and a lot of what you're doing here could probably be done better without, or with limited use of hammer.

Very clever how you had us go through other testing tracks- although I didn't realize that was what was going on at first!