Infinity kappa 9 or kappa 9.2?

I tend to like the driver complement of the original kappa 9 because it is what I am most familiar with, but I have heard at least two people claim that the 9.2 is a better sounding speaker. I have even considered the Kappa 8's to avoid all of the potential problems. I hope to drive these speakers (9's) with two Parasound HCA-1500's, but then hear one person who had trouble with even an HCA-3500 which specs with 8,4, and 2 ohm ratings from the factory.
Any help here would be much appreciated before adding another large set of speakers that are sometimes hard to re-sell. For whatever it is worth one parasound hca-1500 does just fine at high volume for extended periods of time on my current pair of Infinity RS-IIIa's. Many thanks in advance.
Biamping? I assume you meant with one amp for bass and one for mids/highs. I get confused with the vertical/horizontal terminology. Anyway, only marginal advantage that way. Power supply capacity is still determined by bass and intermodulation distortion is relatively minor compared to speaker/room distortions. The other "possible" option of bridging the amps is not a good idea into either of the Kappa's impedance. Better to get the right amp in the first place.

Best advice I can give you is: neither. Not saying that the Kappas aren't very good, they are, but more of a commitment than you expect. Don't make me use the old car analogy. Jump a few generations to Genesis V's (do a search). Ya, it's mo money (probably 4X) and both have proprietary drivers but it's a "sound" investment for the longer run and a better upgrade path.
Not sure it'll be helpful since it's subjective but; after restoring a set of four Kappa 9's I am of the opinion that a class D amp is the ONLY way to go with the 9's. Not that nothing else will drive them...just that you're needlessly burdening any traditional amp by doing so. If you like to turn them up...the loads both can and DO drop well below 1 ohm for extended periods of time. It's not this that kills the traditional's the resulting current draw and therefore power draw (power drawn goes up with the square of the current) that eats the amp. The class D options have become much more proven, available, and price favourable of late so check that out if you decide to go the 9 will NOT be sorry that you did :-D Just my thoughts, Slug
I have a couple of Infinity Renaissance 90, I just bought Jeff Rowland's Capri + monoblocs 501 ... this is an amazing transformation ! ...( I had before OCM 200 + Threshold Fet nine E)

crazy sound staging / imaging ... I can see the player in front of me in the room, how tall the singer is, a lot of space beetween the musicians

I open the full power on the Capri ... it becomes very (too) loud but without distortion and never hard

just great

this said, the idea of the Genesis 5 is a good one ... it depends on what kind of music you hear

good luck
I have the kappa9 before i use a hca-3500 to drive them, but they aren't enough power, the amp keep cliping when deep bass was playing, so i switch to krell ksa-300, the ksa-300 is very easy to drive this kappa9. it even burn the coil in the cossover. so i just upgrade the cossover, i replace all the coil that was burn, and all the cap to solen cap. right now they sounds even more liquid. on my opinion, i think the 9 is better than the 9.2 if you have the power to feed them, the 9 sounds more detail and bass is more quick and slam. but the disadvantage of the kappa9 is the vocal isn't warn enough.
The Genesis 5 isn't better in terms of preformance than the Kappa 9 if you power them properly.

The design is different, but the ribbon tweeters have the same low mass.

I would recommend you get a pair of Kappa 9 built them up new and you will be amazed how this loudspeaker can sound.