Tubes with Infinity IRS Betas

I have always ran my mid/high panels on my Betas with a krell Fpb400cx. A friend let me borrow A pair of Primaluna Prolouge 6 Amps with Kit-120 tubes. They sound really nice but I am not sure if they are powerful enough for the Job. I have a line on a nice set of Vtl 300 deluxe mono blocks. I quess my question is what would I gain with the extra power. I listen at maybe moderate levels at best. 
Back when I owned Infinity RSIIa, (they had three EMIM, three EMIT, two woofers below) I powered them with a Carver. (1985)
I remember he day I played The aria Figaro from The Barber of Seville,  for the entire neighborhood... ( someone was playing very loud music on Saturday mornings a block away.. And on this Summer Saturday I want whomever that was to hear what I was playing.. Opened the windows, put in earplugs and blasted the entire aria so folks two blocks away could hear it clearly.                 
No problem.               
Another time a next door neighbor was annoying me. So I cued up Some hard rock, cranked it up and let it rip. suddenly.               
A few days later the manager, who lived directly above me, told me she was startled out of sleep first thinking a truck had hit the building.... We both laughed.                                  
That was back when EVERYONE was way more laid back...

I like the RSIIa/bs, impressive sound and looks in a single tower configuration. Do you remember what you paid for them? I have a buddy right now who tracked down a good used pair of RS11s, they are nice but not the same without the emims like you had.A few years later (1987) is when I picked up my IRS Deltas, at the time they were $9500 Cdn, I traded in my Kappa 9s and had to sell off a car I was building to help pay for them. I still regret not hanging onto the Deltas, parted with them in 1990 when I moved to another province for work.
We've had several customers with Betas. They used our more powerful amps- so despite the lower impedances they don't seem that crazy to drive. 200 watts seems to do the job.