I have not heard the RS8's, but I have used the Dayton RS series drivers in an MTM project, and I also use the Selah Audio XT8's as my reference speakers. Adding these two experiences together I can only surmise that the RS8's would be very good sounding line arrays. The Dayton aluminum cone woofers used in the RS8 are a bit more analytical than the Vifa XT woofers used in the XT8 - a very slightly cooler sound, but with greater midrange detail. The Fountek tweeters are excellent, and the only reason I didn' use them in the ART array is because using even one per enclosure would have blown the price up to a multiple of what it is with the Vifa dome.

The ART arrays are good sounding speakers considering the very low $350 cost to build, but they aren't anywhere near the same performance level as any of the Selah Audio line arrays. If your budget permits, build the RS8's, and you will have a speaker pair that would cost $15K or so if offered through a mainstream retail outlet.