Hmm. Never had a problem with angels.....aside from intraspecies bullying.
This thread got me thinking of my first tank. I got it when I was little (7 or 8) and, of course, it was set up wrong. It was a 10 gallon and had a few different species (I forget which ones). One of them was an angelfish. I got the angel when it was the size of a dime and it did very well (considering the conditions it was kept in) for over a year until it was literally cooked by my mom. She turned the heater way up when she thought she was turning it down.
Every wrong turn you could make in this hobby was made with this tank. It went through a fully stocked (actually, ridiculously over-stocked) fish-in cycle (the angel was introduced with this first batch of fish). The water was changed once a month, if that. No dechlorinator was used. When the little cheapo air bubbler filter was cleaned, all of the media was removed and the thing was scrubbed with soapy water. So, after every filter cleaning, the tank had to cycle. Let's see, what else...oh yeah, the water was mostly topped off, never really changed. Come to think of it, I can't remember ever actually siphoning water out. I think it may have been exclusively topped off. The tank was a disaster. Yet, in spite of all of this, the angel was the most visibly healthy of all of the fish in there. It ate like a pig. It had great color. It grew to the size of a 50 cent piece (not including fins). Looking back, I'm amazed that fish lasted as long as it did.
So, because of this, I'm always surprised to hear people say that angels are delicate or they need special conditions, etc. Granted, the angel mentioned above would have died much earlier than expected but, according to what some will tell you about angels, it shouldn't have lasted past a few days in that tank, let alone over a year.