Paradigm 3f, KEF reference 3, Monitor Audio PL300II

In this grouping, the MA's are going to be the only speakers that will be full range in room. It faces an issue with integration of the AMT tweeter and the mid range, but I'm sure that isn't surprising and will need a bit more setup work in room in comparison to something like the Kef. The benefit is being the AMT driver offering up a good deal of speed and transparency without becoming exaggerated.

The Reference 3 is going to be the neutral benchmark here. A bit lighter in the lowest register, but this only when compared to the MA's here. You get a lot of coherence, balance, and well placed sound stage and imaging the others won't quite have across the audio band. Nothing will stand out, not much will be missing, and everything will be in balance. The only comment you could lay upon it would be a slight lack of treble air when compared to the Blade2. Yes, that is a notable step up in price, but uses similar technology, it makes for an apt comparison and that well curved baffle is likely the contributor to the improved treble response.

Now the Paradigm is one I haven't heard, but there is little doubt the Persona series has a bit of voicing to it. A bit elevated in the upper mids and part of the treble, which give the impression it will will provide a transparent sound. Going to be a bit bass light and you may want to plan on some sort of sub at some point. This one might need some time listening to see if its something that allows you to enjoy a good deal of your favorite records due to what appears to be a targeted sound. 

Being voiced and bright are not mutually exclusive and B&W is another example of a voiced design. Bad, good, all the ear of the beholder but as you said, its not exactly a forgiving design and you didn't mention the source material as its often a pretty common culprit to bright sound.

Now for the Persona's elevated response on some spots of the frequency response by no means indicate a forgone conclusion the speaker will sound bright, as long as it can produce the ranges cleanly without linearity changes. It does indicate the speakers will need some placement work to get there. The upper treble response is elevated on axis but seems to be engineered with the fall off curve. Its likely something you don't want to have dead on to your listening spot and instead use the off axis response to make the in room balance work. The second is the flare between the mid and tweeter as there is an elevated response area in this range. A bit of that transparent sound is certainly comes from that and I see that upper treble elevation an effort to prevent the loss of treble air due too the tweeter fall off in area.

Knowledgeable setup work would be advised for this speaker more than others. Certainly not the only speaker that is well regarded doing this and this seems to be another design that follows that trait. I might add Focal or Triangle in that grouping as those also have a targeted response and both brands have their fans and advocates on their particular house sound. I think its more a certain sound one might be seeking than anything else. In my own personal experience, I've tended not to enjoy this style as often as I do others.

The Monitors are good speakers, and may be slightly high priced in terms of performance compared to some others in its range. They do provide a differing aesthetic which may speak to some over others. Maybe glossy wood veneers are really your thing! If that was the case, I go for the top end Dali Epicon, as those have some striking wood finishes and from experiences with them are quite good in their own right.

So many good options, so little time!