I did just what Rivid31 did with 2 variations.
Look to my previous post to see the Room 4 description.
In Room 3 I did it close to what Rivid31 did except it seems that Remmiz has now made the second angled platform steep enough that you can't stand on it. So I placed orange portal on the floor under the sign that tells you your heading for that ledge. Then I placed blue on the second platform as high as I could. I jump/crouched through the orange portal so that I came out of the blue at an angle and landed on the top edge of the second angled platform(where I was able to stand). I then placed the blue portal on the highest angled platform. I get as close to the orange portal as I could without falling from that edge that I landed on and I jumped into the orange portal, flew out of the blue portal and actually landed on that little sign that I had put the orange portal under. Its just a short jump up from there and I was on the ledge.
So:
Room 1: 2 portals
Room 2: 4 portals
Room 3: 3 portals
Room 4: 4 portals
Total: 13 portals
Thanks to Rivid31 for Rooms 1 and 2 and the concept for Room 3. ...and for pointing out how obvious a solution I was overlooking at first in Room 4.
BTW, I almost was able to do Room 3 with 2 portals, but I couldn't quite build up the momentum to get high enough. I placed blue on the lowest angled platform and orange about a tile width away from the wall under the ledge(but I was backed up to that wall when I shot it). Then you crouch/jump into the orange portal and try to keep landing back in the orange portal every time you fly out of the blue portal. Its difficult to get a good start, but with pricision, luck, and portal funneling I got a steady circle going. I eventually stopped gaining momentum and the highest I could get was to watch my face fly right at that little exit sign under the ledge. If it were half an inch lower I would've pulled it off.


