Have I personally had problems with carbon arrows? YES!
That old wives' tale about carbons either being straight or broken is pure fantasy. Even though it's been repeated on every carbon arrow thread ever posted, on every archery forum on the internet, it's still a myth. Carbon arrows can, and do, lose their straightness. Carbon arrows also have spine degradation issues. They wear out! Some worse than others. I'd be willing to bet serious cash (assuming I HAD any cash. I AM an archer and bowhunter, ya know[8D]) that many 'tuning problems' we see posted are due to worn out, crooked carbon arrows.
Due to my long draw length, I have to use full length, uncut shafts for my arrows. In fact, some carbon shafts don't even come long enough for me to use. So, any inconsistency or straightness problems are magnified by the arrow length. I have NEVER gotten all-carbon arrows to shoot fixed blade broadheads to the same point of aim. You can't make tuning adjustments when you're trying to work with random groupings, and that is all I've gotten to work with.
I like the idea of carbon arrows. That's why I continue to buy at least a dozen of them every year, hoping against hope that they've improved. Hasn't happened yet.
I can't remember the last time I got a dozen aluminum arrows that refused to shoot fixed blade broadheads consistently. I can count on each arrow in a dozen aluminums to shoot exactly where the others do.
On the other hand, I can't count on any two arrows in a dozen carbons to shoot two arrows to the same point of impact. My yield of good broadhead arrows out of 9 dozen carbons - to date - has been exactly ZERO. No wonder mechanical broadheads are so popular.
Two exceptions: ACC's, an aluminum/carbon hybrid, and Carbon Express Terminator Selects, a fairly heavy carbon/glass composite arrow. If I had to hunt with something other than XX75 or XX78, those would be my choices.