By far?
Try an Orca
I have one. You're right, in straight line speed it can keep up with a Clipper, but not maneuverability.
But that brings up another good point. Look at how many times people have asked for a Clipper buff. The Orca is arguably worse than the Clipper in most ways/roles, is much more expensive, and it's a Large ship that could have been designed to be a Medium ship (no medium sized passenger liners, we go from Dolphin to Orca to Beluga), but "Orca needs a buff" threads almost never pop up.
I think there's two reasons why people think the iClipper should be better. One, is because it's locked behind a rank grind but isn't like the Federation ships. Feds get 3 mediums unlocked through ranks. Granted, those 3 ships behave in a similar way and even share similar hull designs (compare them to Imperial ships, which have more variation in their design), but somehow people think there should automatically be a medium ship unlock in the Imp grind.
And two, because they bought the iClipper, flew it out of dock, turned around, docked again and sold it after they experienced the drift. They didn't give it a chance.
One of the first pvp kills I got was a ganker in a Beluga on PS4, and I was in my Clipper, which wasn't even fully engineered or optimized at that time. They built a ram boat with rails and I had gimballed MCs. I hate bragging, because I'm not even good at pvp, but I they couldn't hit me with the rails for crap, and only got like 2 rams on me. By the end of the fight they were so frustrated they just sat there at let me kill them, which I glady did because this ganker is a persistent murder hobo in CGs. It was EZ. I stopped believing the Clipper was bad that day.
The Asp Scout is bad, and the FDL is OP. Those are the ships that need a little tweaking imo. The Clipper is fine.