I have been on both ends of this debate. I have been the lowly intermediate player playing with a Pro Master, Pro Open and a Womens Open. I did not enjoy that round whatsoever. I felt the entire time I was a burden as I would throw errant shots compared to everyone else on my card. I would be two and three putting while they were patiently standing around to wait for me to get my act together. By the end of the round, you could tell that they were very frustrated with my rate of play, even though I was moving quick for everyone else in my division.
I have also been the MA1 player stuck with two Rec players and a Womens Master player. My rate of play was much quicker then anyone in the group and it was hard to get into a rhythm when I was constantly having to search for the Rec players throws, deal with inappropriate conduct (talking during throwing, advancing down the fairway ahead of other people, etc). I know that my score reflected my frustration with such a slow pace.
While I have no problem playing with anyone of any skill level during a league round or a non sanctioned tournament, I cannot stand it during a sanctioned tournament. Sure it's a great way to meet new people and otherwise play with people you wouldn't normally get to. But then again, that's what before the tournament starts, between rounds and after the tournament is over is for. I will put on the positive face so I do not make anyone feel as if they are a burden but on the inside, it's driving me crazy. I know it's me versus the course but when you have a player grip lock one 50 feet off the tee into crazy brush, spend four throws trying to play forward instead of the smart play to pitch out and continue and then three putt for a 10 on a par 3, it will definitely affect your game. You cannot maintain a rhythm in that situation.
In conclusion, if I have to play a mixed first round, I will ask the TD to place the divisions closer to skill level. An intermediate can play with a rec player cause they aren't that far apart in skill. An advanced player can play with an open player because advanced players want to play open eventually. I think aged protected divisions should play with other age protected divisions. Nothing against any fellow disc golfer but it is quite annoying to move at a snails pace, be the last person in your division to turn in a card and have very little time between rounds because you were stuck with slow moving people.
God, all that makes me sound like a dick but it's how I feel.