Musical Fidelity MC-4 owners:Time to upgrade??

I've been pretty happy with these stand mounted "large bookshelf" monitor-style speakers for about 13 years now. They were designed by Brit audio engineer/equipment reviewer Martin Colloms, who knows a thing or two about speakers. When I bought them I was planning to buy Spendor SP-1s which were fairly new at the time, but these MC-4s were much better in my A/B comparison (they were more dynamic, open, and free of box colorations). I really wonder how they're holding up against newer speakers, however, and wonder if anyone out there has them and can comment on this.I am prepared to upgrade to one of the current monitor-type speakers, the largest I can accomodate in my present set up, if I can get a feeling as to which way to go and what to listen to as possible replacement. My concern is that there may have been very few pairs of MC-4s made and maybe no one knows about them. Thank you.