If I were to have one float rod, I'd choose the Acolyte Specimen in the 15ft. I end up using it most of the time these days and I haven't fished for barbel with it yet. It suits my style of fishing - trotting, casting big floats and 5-10g olivettes about, it feels crisp in hand and nicely sets the hook at range. It has a fair bit of poke for when fish get in the fast flow yet has a soft tip. Ideal for grayling, chub and decent roach on the Hampshire rivers. It never feels over gunned but is tippy/progressive in the action.
I'm even thinking of getting another and releasing some of my other rods. As for light ledgering on small rivers, I wouldn't use an acolyte as they're designed for commercials. If it's roach/chub you're after, on rivers better to get something which has a tip with a much slower action, my favourites being the old Drennan Medium Feeder rod and a Tricast Trophy, much older rods that are a lot cheaper as they're secondhand and IMO better. I'm not much of a stillwater fisherman but don't really see the merits of a fast carbon quiver tip on a stillwater (all Acolytes have carbon tips) either.