@Golum
The Marten Heritage line is is the most refined and natural sounding I've heard to date, but system matching is key. The Accuton ceramic drivers are among the worlds best, and yet, can very easily be made to sound fatiguing with bad matching. It looks like you're running a digital front end, and I'm not familiar with your particular DAC. My experience with Marten Heritage speakers is limited to Duke 2 and Bird 2, and then, mostly analog front ends. My friend owns the EAR DACute DAC (in addition to top notch analog front ends) and listens through Marten Bird 2s with the diamond tweeters. At his house, while the DAC sounds nice (mostly due to its Wolfson chip and transformer coupled tube output stage), it doesn't compete with analog in terms of emotional engagement. Digital tends to sound more claustrophobic and less full bodied than analog on Martens, and I would not suggest making a speaker change unless you've auditioned them in home. Especially given the fact that you seem very happy with what you've got!!! Then again, I've had much the same observation regarding digital on most high fidelity systems, and don't want to start any religious wars. Just giving you my firsthand experience with Marten. ;-)