Its true about some of the angles being virtually indistinguishable from each other, some are easy, some arent. Figure out the easy ones by eyeballing them, but if you cant tell the difference use the paper ruler. Thing is it does take a little time, so you have to be able to JAM on the other sections, ie cube counting, and hole punching. You should get to the point that you can do those sections in practice (ie Topscore and Achiever) in no more than 5 or 6 minutes with reasonable precision. That will leave you enough time to get those hard angle questions right.
There have been plenty of posts about the paper ruler, and it is worth finding out about, trust me. It could make a huge difference in your PAT score. To summarize, yes, the angles are really hard, but if you practice getting your speed down and practice using the paper ruler, you should do fine.