I don't have anything against any manufacturer's marketing hype since they all do it to impress consumers. Whether the PLUS version is really vastly better I could not tell you. Never been a brand name snob although I've worked for major OEMs, I compare specs and what I need to do on my part to keep the product functional for as long as expected. Plenty of horror stories of high-end batteries improperly cared for suffering an early death.
Since I've never encountered a problem with any of my RV golfcart batteries I will continue to purchase them at Samsclub, last set of Interstates lasted 7 years and were still functioning when I traded them in. Got a new set that has an extra 30 amphours as I had a gift card to burn and price was too good to pass on. More important is maintenance and charging, although Iota IQ4 is pumping 14.8Vdc, it is a rare event to have to add water during monthly checks.