I've had the opportunity to audition the Dynaudio Contour 20i speakers, and I must say, their sound quality is very impressive. According to Stereophile's review, the Contour 20 speakers pair well with two modest class A tube amplifiers (with 22-35 wpc), but they don't seem to favor a 400-watt per channel class D amplifier. This suggests that the compatibility issue lies more in quality matching rather than sheer wattage power. Given that a pair of used Contour 20 speakers is available at half the price of the new 20i model in the market, it's definitely worth considering.
My third system comprising NHT SB3, almost the same spec with 20/20i, performs quite well in my even smaller room. What has been confined / compromised is soundstage due to space constraint but the rest of sound attributes can be tuned well with care.