McCormack DNA .5? Do I need more power?

Hi. I have been thinking about picking up a used McCormack DNA 0.5, which I may upgrade in the future. Will it be powerful enough at only 100w? I am currently using a B&K Reference 4420 (225wpc) and while it sounds good, I am sure I will get better sound out of the McCormack, especially once upgraded. My speakers are 91db, pretty efficient, but they have a big 10" driver along with a 6.5" driver, 1" driver, and tweeter, so I don't want to under-power them. Manufacturer recommends no less than 30w. I don't play real loud (no higher than 10 o'clock, which is plenty), but I don't want the lows to be muddled by a lack of power. What do you think?