Great topic. I started my mycology adventure using the ASFGNAWM also. Early in my identification years, I came across what I thought were parasol mushrooms. If I remember correctly,, the field guide mentioned that the toxic lookalike was uncommon and could be positively identified by the spores under a microscope. I didn't have a microscope, so I played the odds. That was a HUGE MISTAKE! I honestly thought I was going to die. The vomiting was indeed violent and frequent. It lasted for three full days and dehydrated me, took all my energy and I felt like I was only moments away form becoming corpse finder matter. With the naked eye, I really don't think there's enough differences between the two, to positively identify, but the book does describe the spore shapes which distinguish the difference. I'm only going by memory, so I might be mistaken in a point, but I will never forget what I went through. The lookalike is toxic enough to become fatal. No mushroom is worth that risk. That's why I have become a proponent of 100% positive identification before SAMPLING a new mushroom.