I just want to be sure with the portals that over the doors, you are detaching them anyway. Essentially just making a flat plane in front of it. That said, couldn't i just make a plane under the map and raise a checkerboard pattern making more portals and less lag then a neater door only?

Alright. I'm no expert in portals but here's the essense: There are two types or portals. +portal and +exactportal.

+ portal is the loose type. The one you use generally, following general areas of the landscape. They can be helpful.

+ exactportal is the one you use to SEAL areas into clusters. They are the most effective. The way they face, is most important. Also, if you're using them, they need to be kinda close one to another if you're trying to seal off a large area.

i found this not bad to watch about setting them up.
http://www.youtube.com/watch?v=3SqygQGcPgU&playnext=1&list=PL97A6E1AEB6A1D637&index=19

Thank you both.