Well, now that I've used my Zx1s for a while I can say that they are very good speakers. I can see them being use for floor monitors for Karaoke, mains on poles over EV Sb122 subs and even using them alone without subs for small audiences/small venues of under 50 people. I've used them for a bunch of senior citizen shows in small rooms with maybe 35 people and they were way more than enough. The most common comment I get is "it's too loud, can you turn it down?" For small audiences they're overkill and considering their small size the bass is impressive.
I've even used the pair of Zx1s and one Sb122 sub for a senior performance in a large hall in Tampa, maybe 100 ft x 60 ft and they still asked me to turn it down and I barely had it turned up. I don't have an amp powerful enough to not clip at high volume levels so I don't know how much power they can really handle. I do know that a pair of Zx1s and a pair of Sb122 subs can do a wedding of 250, maybe even 300 people no problem as long as you have a good, powerful amp. My amps go to 500wpc@4ohms max. I've never tried the speakers with anything more than that.
The sound is clean and clear and very good for vocals. I used them last night for my singing show I do. I can totally blow away a small 2000-3000 sq ft room, no problem.
The Zx1s are kind of expensive IMO @ around $250-$300 each, but they are really small and light weight and that's really important to me. I got my pair off ebay for $365 for the pair and that is even a lot of money to me. My 12" EV Sx100+ speakers blow the Zx1s away, but they are much bulkier and weigh about 30 pounds each.
I would love to hear the FBT Jolly 8 speakers, but I doubt I will ever get the chance unless I just buy a pair. As good as they appear to be, I wonder if FBT will EVER have wide distribution in the USA. Same unfortunately for RCF, but I'm very reluctant to buy speakers without ever hearing them.