Hi. I started with pernamax and then changed to maxaflex. I loved it but the only reason I changed was that the maxaflex also contains glucosamine, MSM and HA as well as the green lipped muscels, and I thought I may as well do the whole lot.
I use it on 2 old eventers who are both still going strong and competing in their 20s, they go fantastically always doing their best and it's hard to believe their age. I started because they could be a little stiff over the winter in the cold/wet weather and they are stabled at night as opposed to living out in the summer. I still make sure I warm up enough but neither has a hint of stiffness since starting on it.
May not be relevant but I also started using the canine one on my dog who has arthritic paws and I'm not convinced it helps her. Although in saying that have tried many things and not convinced on any of them at all!