Thank you @Steve Herschbachfor all the details, so it seems I either have to choose if I prefer using a 2 piece for sturdiness in water or a 3 piece solution for an easy go on carrying with me in a relatively small backpack: a combo is unlikely to work perfectly in both ways.
A friend of mine has a Detect ED that I can borrow to try the 2 piece rod, I'll finally try it (in water and tucking it away) and I'll take my final decision.
Thanks again for all the infos you, @phrunt and @steveg (those colored carbon fiber tubes he creates are... "darn sexy"! :D) where able to lay on the table.
@steveg awesome work on your rods, I'll send you a request in a PM as soon as I figure out what's the prominent feature I will settle with.