I think if you are still relatively young with undamaged hearing, the Personas are a bit difficult to listen to on-axis because of the W frequency response. It's quite similar to the old B&W 700 series in terms of tonality. Which is to say, it "works" for people who may be older and have gone to a few too many rock concerts and need a smiley curve EQed speaker.
When I was testing between the Paradigm Persona B, Dynaudio C1, Kef Reference 1, and M126BE, the combination of the big soundstage and rising response made the Persona B not just the brightest out of the 4 but a real struggle to listen to for extended periods of time. I'd say the C1 was the easiest to listen to for a long time because it was so dark (aided by poor dispersion which Stereophile correctly calls it a "mellow" sound signature), followed by the Reference 1. The M126BE seemed the 2nd brightest but it was mostly a result of the reflections from wide dispersion adding a lot of airiness, whereas the Persona B's direct sound was bright/fatiguing.
If you listened to them off-axis I think it was alot easier to deal with but I still couldn't see myself using them for long listening sessions.