Saw the most recent Linkwitz kit at RMAF, the LXmini, which sounded very nice for its price of $400 or $475 (with cnc'd wood) (link). Depending on how my current speakers sound when the Rag comes, I might build a pair. Bass was strong but controlled (obviously will depend on room treatment), mids were excellent and highs were rolled a bit. Maybe not the pinnacle of sound, but they are small-ish and inexpensive. You don't even have to do any woodwork if you get the cnc'd parts, it's straight assembly from there. I liked them better than most of the speakers at the show, regardless of price, including the KEF LS50, which were great as well. The LX521s were more resolving and better transitioning between frequency bands, but not significantly better overall, I thought.
 
Info here: http://www.linkwitzlab.com/LXmini/Introduction.htm

Neither? The webpage says it has a crossover at 700Hz.

It sounded like it had enough volume and extension for most music without a sub. For HT use you would need a sub.

Different philosophy Linkwitz has. May as well throw Rag and Yggys into garbage and get some cheap Emotivas to stack if going with any of Linkwitz's designs.

I'm not a big fan of the MiniDSP stuff. Basically you will be taking output to a digital processor. ADC-DAC again (or just DAC is you use MiniDSP as the source). Separate modules for bass and treble. Advantage: no power / life sucking or veiled passive x-overs. Disadvantage: will ruin sound with crappy cheap DSP / bit manipulation.

Not saying it's bad. It will sound good. Detailed. Precise. Only limited by the drivers. But to me it will lose immediacy and sound uninteresting, sterile, and flat. I did similar DSP stuff with earlier speakers. So moved beyond that.

There shouldn't be any reason you can't implement a passive xover with them. But you would have to mimic the transfer functions with passive components. And that might turn out to be a bit pricy itself depending on your taste in caps/inductors/resistors. Actually, it shouldn't be any more expensive than a miniDSP box so long as you don't chase the dragon. And if you've already settled on the Rag you'll be saving $$$ anyway.



I could try to mock something up for you in LTspice if you're interested in going that route. I'm also interested in building an omni after I bring my OBs to completion. This one looks a fair bit cheaper and easier than the Pluto.