I've thought about it, but decided not on the following grounds:-
1) I normally sleep on my front/side. I don't see how that would work in a hammock, so I'd have to get used to sleeping on my back. I'd expect that would take about a week at the start of each tour.
2) The chances of setting up a hammock in most European campsites are fairly minimal, so no making use of campsite facilities at intervals for washing you or your clothes. Likewise, it pretty much commits you to wild camping, and mostly at relatively low level.
3) A hammock and rainfly isn't any lighter than a lightweight tent, and may be heavier (going by the Hennessy Hammock figures).
4) I'd imagine a fair bit of scouting around would be needed to find somewhere relatively discreet, with 2 trees an appropriate distance apart without a load of undergrowth getting in the way, and that was accessible enough to take your bike to.