I've got the Royd Sintra 2 on my office computer, and they sound really great. They're currently driven by my
DIY FrankenAmp (dual mono, with each channel comprised of a Hammond 18-0-18 transformer, Avondale CAP6, and Naim NAPA5 from my NAP110). They're fed from my computer's S/PDIF TosLink output into a MiniDSP 4x10 that's being used as both DAC and pre-amp. That MiniDSP is destined to be used as an active crossover for my PFM Special build, coming "soon", at which point I'll swap in a Benchmark DAC1.
Be careful not to overdrive the Sintra 2, especially with bass signals. I was using them as studio monitors when recording a bass track, and I think it bent the voice coil a bit. Consequently, if you play certain notes through it at higher volumes, there's a bit of a buzz. That rarely happens, though, so I'm quite pleased with them where they are.