As for the JM Labs... I know them well, as they used to form part of many of the systems demonstrated at Acoustica (in Chester), when I used to work there, although that was mostly with Naim gear. However, I'm well aware of their inherent sonic characteristics and 'house sound', which is typically French. You could hook up, for example, a pair of Triangles, and achieve a rather similar balance.
I enjoyed listening to the JM Labs, as it brought back memories, and it's difficult to find any major fault with them, certainly in a hi-fi sense, although their top-end 'sheen' and rather insistent treble emphasis, together with their somewhat overall 'cold tone', could be a problem in some systems, although it wasn't in yours.
Certainly, the JM Labs are more than good enough to tide you over until you embark on that active JBL set up you proposed. Furthermore, for analysis purposes, it's useful having access to a 'sorted' pair of speakers, amongst your semi-functioning 'vintage pap'
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