Nice version, the mirror option is a great idea
But sometimes the reflection isn't 100% at his optimal use but the was a well know issue when using the template reflection.
Just look at this screenie:

Another remark is that when I shoot the portal at the floor and not at a wall, the first "pre portal" is being projected 90° facing off the ground, when I shoot a second time, the "real" portal is being projected against the floor as it should be, just look at the screenie:

But beside these errors, it's still a nice project tompo

Cheers

Frazzle