I think watts are highly overrated and not always what leads to a dynamic, effortless sound. Bandwith is important, as is speaker to amp matching. I have a pair of Cube Audio Nenuphar Mini's. 92db efficient. I used a 150 high current solid state amp which is highly regarded on these forums and can drive speakers to 2ohms easily. It sounded ok, but a bit flat. Turns out the amp is highly damped. I don't understand damping much, but others with my speakers suggested amps with less damping, even amps with as little as 3 watts. I tried a small EL-84 based tube amp with 14 watts -- 14 watts?! Yes, 14 watts. Wow, the speakers opened up. More depth, more space, more texture in the bass. The sound was more organic, real and alive. The SS amp had a "strong" sound. It sounded good, very good, but it was less deep, more on 1 plane, and just didn't sound alive, textural or nuanced, and it didn't have the contrast in sound that really leads to dynamics. Could I play it loud enough to destroy my speakers and ears? Yup. Was it clean? Yup. But it wasn't making me want to keep listening. The amp did do better with other speakers and it is a great amp, just not in this case.
Now, I'm not saying those of you experiencing better sound with higher wattage amps aren't experiencing bliss with them. I'm just saying don't always equate this with watts. There's a lot more to what makes the speakers sound good. BTW, I follow the Spatial thread because I want to try X5's one day, but my space just isn't right for them right now. So, enjoy your speakers because at the end of the day they're yours and its your system, your music so if its what makes you happy and keeps you from turning off the music then go with it. Just thought I'd share my experience.