I think the Merlins are a fantastic speaker. Certainly one of the cornerstone products of the industry in the past decade.
The assertion was often made that Vandersteens do so much right, while minimizing/spreading their faults out so well, that they are probably the best overall loudspeaker available to us. And, by "us", I mean the 95% of "us" in this hobby. However, in my opinion, it's the Merlins (along with MAYBE one other company - but if you put a gun to my head, it's Merlin) that deserve that title.
Are they the right speakers for every audiophile? No! And, that is true of every loudspeaker.
But, for your investment in a new or used pair (and, I'd suggest to talk to Bobby before purchasing any used), the odds are that you'll have a pair of loudspeakers that will serve you for a very long time. And, how many other high end audio products can that be said about?