I should also note that these speakers are happiest with a higer output impedance amplifier. On mine i most often use a set of highly developed RH84 monoblok variants (4W). Chris uses SE 2A3 (Bottlehead), SE 300B (Wright), SE EL84 (custom Vaughn) or a lovely little class A 3W PP EL84.
They also work well with a prototype SS variable transimpedance amplifier we have (you just dial in the appropriate output impedance), and i've heard them sound wonderful (and play louder than i thot possible) with a 25W monarchy Class A. Field reports are that the Firstwatt F2 is a marriage made in heaven.
If you have a large room and want to play fairly loud you'll need 10W or so
Bass into the 60s is what i suggest in most cases, but there have been field reports of the 30s, and i have measured into the 40s in 1 room (i'm sure the latter at limited levels).
With the treated drivers, the right source and amp, these have gobs of finese and imaging is second to none. These are not "hifi", they just play music.
If you want to compare against commercial, i picked these over a set of 6k Sonus Faber standmounts.
dave