Any reviews of Southern States' Fiber Plus feed?

I need to make feed changes for all three of my horses, for various reasons. To keep the story short, here’s a quick summary of each horse and the problems it’s having:

Horse 1: 19-year-old TB mare, has been an easy keeper since she was a weanling, but the last two years has lost a lot of weight over the winter, still gets a little chunky in the summer. Pasture-boarded, currently on Nutrena Empower Balancer and ProForce Senior. Lower level dressage horse.

Horse 2: 13-year-old TB gelding, recently had blood pulled for recurring slight bouts of laminitis, found slightly elevated insulin and leptin. Vet wants to try to control it with a lower starch diet. Getting the same feed as above, was put on Senior after a bad reaction to a tranquilizer for dental work led to a dramatic weight loss. Also pasture-boarded and tends toward porky in the summer, loses in the winter. He’s my husband’s wtc, low x-rails horse. We’ve kept both of these horses at a pretty steady 5/6 body score for the last year by upping feed and adding hay cubes in winter, cutting back in summer. Both have decent pasture.

Horse 3: 11-year-old TB gelding, just purchased a few months ago. He was in great condition when I first tried him, dropped a little when we had a really bad heat wave right before his pre-purchase, but was still a 5, then dropped again when he moved. He is pasture-boarded at a different barn. This barn feeds everyone a Legends ration balancer. Because he was moving from not much pasture to a pretty lush pasture, he regained some of the weight, but as his workload has increased, he has started dropping a little weight again, and definitely needs to be getting something extra. He is just starting training as a jumper.

All three horses work 4-5 times a week, 30-45 minutes, mostly trot and canter with a couple of short walk breaks. I’m looking at the Fiber Plus because Horse 3 was on it when I bought him, and I liked the way he looked. From what I’ve read, it’s low starch, but still has a relatively high fat content, so might work for the others as well. I’m also looking at the Triple Crown Senior, which I know has low NSC values, and high fat. I’d like to keep all on the same feed if possible just because it’s easier, but will do different feeds if I need to. Anyone have any reviews of the Fiber Plus, or suggestions for other feeds to look at? Purina, Southern States, Triple Crown and Nutrena are all fairly easy to get around here.

TIA for any suggestions and information!

Did you decide to go with the fiber plus? Wondering how you liked it?

I was previously at a barn that fed the Fiber Plus line from Southern States and all of the horses looked great, held weight well and coats looked nice.
I moved to a different barn, fed Dynasport, barn switched feeds, and I opted for buying my own feed, kept with Dynasport, but that price adds up comparing $27 a bag to only $16 for Fiber Plus! This was for my previous mare.

My current horse, a growing 2 year old filly, was on TC Growth, but I kept finding corn in my bags, which was just annoyed me enough to go ahead and switch her over to Fiber Plus, she likes Fiber Plus better and cleans it up way quicker, and percentage-wise they’re pretty similar and more consistent. Highly recommend Fiber Plus!