HELP! need feedback

Everything was going along fine and then yesterday we went up to the Penland area for an annual potters' market and to visit a couple of galleries.  So of course I had to put on my artist duds and test drive some of my new pieces.  I had in mind to wear a couple of the raw cube necklaces.  I wanted them to be long and sit one just above the other.  That's when I realized the lengths needed to be adjustable, or at least I'm thinking that the lengths should be adjustable.  I love the look of really long pieces ... you know like 36" and more.  But that was way too long to wear with my inspiration sweater.

Here's the three I had to choose from ...

I thought I had the whole closure thing figured out.  But I'm not feeling so sure right now ... amazing how difficult it is to design and engineer interesting, clean and elegant solutions.  Kind of surprised, but this little conundrum has me kind of deflated.   

This is how I thought I would finish most of the new work ... a fixed closure, the necklace cords are long enough to just slip over the head - I was making these pretty long - 32" to 36". 

I've been in a bit of a snit all day trying to take a step back, not stay annoyed and solve my design problem.  This is the adjustable closure I came up with a while ago.  It still slips over the head, but there's an overhand knot next to the fossil that slides on the cord. 

I thought this looked pretty cool, fit in with the overall theme and functioned well.  Dave, who has a  pretty good eye for design, wasn't convinced.  He didn't think my customers would want to mess with adjusting the cord ... I'm not so sure. 

He was thinking I should do my regular button/loop clasp ...

For years, my closures have always been a KVK button and loop or the forged hook and link (which is silver and doesn't fit in with this work).  I really want something different for this collection. 

HELP!  This is where living in a near vacuum has its problems.  Any opinions here?  I'm definitely not usually one to design by committee, but I would very much love some feedback, opinions, insight ... hmmm, insight's probably my responsibility, but feedback would be lovely.

with deep gratitude ...
l i g a - kvk