Larsen speakers: 4.2 or 6.2??. Has anyone heard or own them??

I have listened to the 6 & the 8, but I didn’t compare them to the other models you mention (and I don't own them).Having said that, onto the experience: they were both very conveniently placed against the front wall (we still played with small angles & right-left positioning, but against the wall gave the best sound). They both gave a realistically 3D soundstage, albeit not very focused like, say, a medium-sized ATC. The dynamics are OK, again not like an ATC, but well above average). Overall, the 8 gave a fuller, larger and more convincing sound—but do note that I listened to classical music, full +100 instruments orchestra. The 6 are not very big, which may be an additional advantage.
BTW, we used a 100W class A amp that was only just enough to power them! Switching to the big MF nuvista (8000? 800?) gave a bit more ease to the system.

I have owned all three models of Larsen speakers, 4/6/8 and I used to be a dealer for these.  I think that Larsen speakers provide excellent sound, excellent value and are very easy to live with due to the easy placement options: 1- find the longest wall in the room, 2- place the speakers directly against the wall (no toe-in), 3- move speakers apart or closer together until the you hear the best imaging, 4- pour a cup of your favorite beverage and enjoy.

I don't understand your comment re: the price difference between the Larsen 4 and the Larsen 6:

Seems like a lot of money for a two way speaker despite the fact that the design eliminates most placement problems and can be placed against the wall ( so say the few reviews I read of both models)

I can think of a lot of 2-way speakers that are more expensive than the Larsen 6.

In any case, the Larsen speakers all provide a recognizable house sound; the larger/more expensive models just provide more of it in larger rooms.  Larsen's are some of the most tonally accurate speakers I have ever heard.  A fair proportion of my clients were professional musicians (think more vocalists, classical and jazz music rather than hard rock.)  That's not to say that everyone will agree that these are the best speakers, nor would I.  But I will say that the Larsen's are probably the speakers most easy to live with that I have ever owned.

I have owned Ohm speakers and Maggies.  Both have good points and things they do well.  But neither was, to my ears, as good as the Larsens in my rooms and playing the music I listen to.  Not by a long shot.

One last observation: I am friends with the Michael Vamos from Audio Skies, the NA distributor for Larsen, Gamut and Pear Audio.  Michael has every speaker he sells available for listening in his home.  Yet many times I would go see Michael and he was listening to a pair of Larsen 4s.  When I asked hi why he wasn't listening to something more expensive his answer was that the Larsen 4s always amaze him at how good they are for the money and that they make him happy.  I can't think of a more apt description.