I have Acolyte Ultras and Pluses, and plenty of other choices of float rods. As far as I'm concerned, the Ultras are light actioned for a modern match rod and the Pluses are a slightly heavier actioned version of the Ultra. If your idea of a match rod is rooted in the 80s and early 90s, the Ultra is broadly comparable to a match rod of the era. With that period in mind, the Plus will seem like a beefy rod. However, compared to plenty of modern match rods, let alone specialist/specimen float rods, they aren't.
The Ultras have stated optimum reel lines of 3-5lb, hooklengths 1.5-4lb.
The Pluses have stated optimum reel lines of 4-6lb+, hooklengths 2.5-5lb.
It also states that the Plus is "slightly more powerful" than the Ultra. I don't tend to give great credence to manufacturers line ratings. However, I'm not inclined to push the envelope too far with the Acolytes.
Though I consider the Ultra to be a roach, dace and grayling trotting rod, I've landed big chub with it without problems. I consider the Plus to be primarily a chub rod, but don't have an issue with the odd barbel crashing the party. If I were specifically targeting barbel, especially with heavier line, the Acolyte plus would not be the rod I'd reach for. I'd also mention that I don't much like the Acolytes on stillwaters. Nice trotting rods with an action that I find well suited to such methods.
I suspect that an awful lot is going to depend on the age (what exactly they think a float/match rod is) and skill of the angler coupled with the intended venue. I'd advise that no one thinks of the Acolyte Plus as an out and out big fish rod though.