Most of the time i play with the same group of people. I am a lot better than them, but they are a lovely bunch of people.
The biggest issue with them and anything above a +10 is that they under estimate fortified/tyrannical. Trash needs to be interrupted and bosses need to be done near perfect.
This means actively remembering what trash does what, and the same with bosses.
A lot of newbies and casuals just need to actively remember abilities, mechanics and give the 3rd affix the respect it deserves. Especially if going for keystone master