Upgrading Maggie MGIIIa's to 3.7i - worth it?

I'm suffering from upgrade fever but nothing is easy.  I'm quite addicted to the Maggie sound so considering an upgrade from my ancient IIIa's to 3.7i's.  But of course there's a catch - the old MGIIIa's got a full factory rebuild a few years ago. This entailed new membranes/wires, tweeters and covers.  At the time Magnapan said they'd be "much better than new."  And so it was.  They sound great!

And so, the question:  Is the upgrade to 3.7I's worthwhile?  To be worth it the improvement would have to be substantial, not just incrementally better at this or that.  What might I expect? FWIW, they're being driven by a recapped ML No. 322 which drives them very well indeed.  Any thoughts?  Thanks,