mramos1, I also have had excellent results with P-n-P on all size boards and I use an iron despite having two laminators sitting here next to me.
But I must make a few comments.
1) I use a copper cleaner, fast an easy, rinse and dry with paper towel, don't touch copper surface with fingers. No solvent needed.
2) De-burring an absolute must.
3) Max heat can be to hot and cause the toner to (cook) make pit holes. Recommended heat is 300°F , +- 25°F, some irons get hotter than that, mine does. Caused much trouble until I found right setting.
4) I use a clean piece of paper on top of the P-n-P, makes the iron glide easier. I also use a wooden cutting board with about a dozen pages of news paper on top to place my PCB & P-n-P on, this helps to retain the heat and seems to help distributing it more evenly.
If your PCB is not perfectly flat make sure that you try to follow the curvature with your iron.
This work so well that I get 99.99% good boards.