I personally love the thing, but I can see how it's not everyone's cup of tea as Karplus Strong synthesis does rather stand out.
That being said, it being MN ensures that there is a TON of modulation options available ehich makes it incrediably organic. I like the switch from beautiful pluck (kind of it's "default" sound) to harsh digital noise with everything inbetween. Dual 1v/O & excite inputs can produce some amazingly complex sounds and crazy duophony.
I'm sure the sale of MN's tELHARMONIC has spurred a few to sell, however, it's probably a great time to get one as you'll probably end up picking one up for £150 with some gently bartering.
BUT you'll need a sweet analogue VCO (or 2) to support this module, it's a tad too unique to be a stand alone single VCO which may have truened some ppl off. I've also heard some complain about the tracking, however, it's odd behaviour is the reason I want to keep it - it does stand out in the crowd!
Obviously check out the MN online demos on YouTube.
Hope that helps!