Point Source or Line Source?

Dispersion: Both good. Line source disperses very little vertically which avoids ceiling and floor room reflections. Point source disperses uniformly both horiz. and vert. producing (some say) a larger soundstage/sweet spot.

Output: Line source (whether a ribbon, or a vertical array of conventional cone,dome, or electrostatic drivers) require only a little work from each driver. So they can (all together) produce fairly high volume with low distortion. Point source need to be as small as possible to approximate a point, so they must be driven hard to move any appreciable amount of air. They must therefore be made of stiff and light (exotic/expensive) materials, and employ clever strategies for keeping them cool so the voice coils won't burn out.

I can't say which is better because their are too many variables that affect both their ability to produce realistic imaging and sonic signatures.

Impossible to answer definitively in my opinion, even if we write a virtual book here -- there are plenty of potential tradeoffs to each in the real world. Frequently this question also entails choosing between mono-polar vs. bi-polar vs. di-polar radiation patterns, and planar/ribbon vs. electrostatic vs. dynamic-cone/dome driver types as well. And there are as many different versions of 'point-source' and 'line-source' as there are models of speakers -- no speaker can actually achieve true point- or line-source behavior (most either partially simulate one at best, or don't even really aim to), so there are as many differences among dispersion patterns between speakers ostensibly of the same catagory as there are between speakers in different catagories. You've just got to pick your poison based on your own preferences, priorities, and perhaps limitations. Bottom line is that any speaker, using any type of technology and/or configuration, is going to yield one idiosyncratic take on the sound absolute -- with its own set of pros and cons, and implications for factors such as listening style, musical tastes, and requirements for partnering room and system -- which won't be the same as for any other speaker, whatever the similarities or differences of the design approaches taken. You might be able to make a few broad and imprecise generalizations, but ultimately you're buying a speaker, not a type of speaker, and some other speaker will always do something better than the one you've got...

It might be helpful to do some listening, with your own familiar recordings, to a few good examples of each type. They say a picture is worth a thousand words and I would say that first-hand sonic evaluations can be equally valuable...

Well said Zaikesman . I have line source {Pipedream 21 } and have owned many point source speakers. Line source speakers are trickier to dial in imo but locked in the right position , are capable of realistic frequency response swings. You can sit much farther away than with point source designs. Point source designs usually have better sonics off axis as well.