I've tried the VR4jrs with Brystons and Aleph 0s. Just excellent really. Again it is a matter of taste in what type of "sounding" amp to use. In a seperate set-up, we've tried (and are currently using) a Manley Stingray (35 watts) to drive the 4jrs and they are driving them fine. Room size is around 4m x 5m. Volume levels used were reasonable, no head banging levels.
If you're using a tube amp, just make sure you have enough lead shot in the 4jrs to dampen cabinet resonances. This likewise helps in making it easier to drive as it lessens impedance dips.