Some discussions already on this:
http://www.monsterfishkeepers.com/f...7-Southern-Delight&highlight=southern+delight
http://www.monsterfishkeepers.com/forums/showthread.php?444945-New-Food&highlight=southern+delight
I will start with the fact that I mix different pellets. This is my choice and I know some say it is not the 'ideal' method but my fish are thriving and I am happy with the overall results. I use NLS, Dainichi, Hikari, Omega One and Ocean Nutrition pellets in my current mix of foods.
I got some samples of Southern Delight, specifically the Large Cichlid, Powerfeed and Growth and my fish did not reject it at all. This is likely due to the fact I typically mix foods and they have learned to eat everything. One thing I liked about it was that it was a clean pellet. It did leave a little surface slick but did not powder up when the fish ate it. Some foods my fish just love to grind up and make a big mess with but they swallowed these whole and did not make a mess even with the large cichlid pellets. I noticed too that I did not have as much of the 'bath tub' ring effect from feeding these as I did my normal mix. When I did my gravel vac/water changes it seemed waste output was reduced and I was not noticing a huge amount of red colored waste as I had been seeing before. These were just my observations from using the food exclusive for ten days. I liked what I had seen from its use and have added it to my current mix and decided to purchase some bulk pellets to continue to use.
Just for the record, I do three water changes with gravel vac per week and this is always consistent, so I know what to expect with my cleanings. I also measure out my food and put them in pill containers so the fish receive a consistent amount of food each day at the same time. I think I did a realistic test of the food and to be truthful because it was new I fed a bit heavy handed compared to my normal food mix. I would throw some in as a treat more often than my normal feeding. If I were going to have issues it would have presented itself more quickly.
I hate these forum posts on food because they turn into ugly debates. I kind of like the fact the guys at Southern delight are starting off with kind of a quiet start. No strange 'snake oil' claims of what the food can do. Just my thought on it.