Still totally torn, but leaning towards...

The more elegant solution/what we wanted all along.

As I say, totally torn.

Apparently I have three halves [or three hands, if you prefer!]:

1. Half of me wants to leave the joists as they are - having to duck under beams, for a few tall visitors isn't the worst thing that could happen. [And then the lovely carpenters won't hate me!]
2. Half of me wants to seize the opportunity to "fix" the "problem" - getting Laurent Mazij to re-do the woodwork of the corridor at this stage adds about a day's delay/won't cost too much and we end up with the headroom that Jean-Marie was assuring us that we have now [till Michel Mazij proved otherwise], with the added bonus of no step up in the middle of the corridor
3. Half of me is still so pissed off at T+B's recurrent failure to listen that it wants to "teach them a lesson". This is the "half" of me I don't want to listen to...

If we discount the vindictive "half" [and I think we should; that's never a good motivation], we're left equally between not wanting to upset workmen and to get what we want.

Well, now I'm leaning towards getting what we want... I emphasised to M. Mazij snr that we were very happy with M. Mazij jnr's work, but it's the 6'+ visitors that are the problem. As I see it, we can endure a day [two at max] of delays, and a little extra cost [that we WILL be negotiating about with T+B] now, or have the step remind us every time we go along there that we didn't take the more difficult course of action.

I'm usually pretty good at facing up to doing the difficult things in life, and I know that in six months time most carpenters will have forgiven us, and I will have forgotten about it!

If you remember the superfluous beam - we've never yet regretted that extra cost, and it looks as if it's been there as long as the house. Whereas some of the other "issues" that we noticed when it was too late to fix [the stupid VMC route, for example, or the badly placed flue for the woodburning stove] we are repeatedly reminded of the inconvenience they cause.

With the VMC housing in the middle of the drive: if I won the lottery, that's the first thing I would get rid of - I'd take up the floor upstairs and take the pipes out the back of the house!

So it's seeming as though "bite the bullet" but then forget about the issue once it is resolved is my preferred choice.

David was leaning the other way, but I think when I mentioned that this is one problem we can fix, as it's not too late, he might be having second thoughts.

As we've left it, I'm fairly sure that M. Mazij jnr will be arriving tomorrow morning expecting to start undoing his hard work. If I say nothing, that will continue, so it could be that the hard bit has already been done [by my not saying, "no that's fine, leave it as it is"]?

In 24 hours I will find out what our decision has been!

ETA: I have measured a couple of doorways, and they are 2.01m and 1.91 m, but somehow ducking under a beam catches people out - I think it's because you can see above it, it fools the eye - whereas seeing a solid stone wall above the lintel gives the message "duck or grouse" pretty convincingly? And those doorways already existed, whereas we are having to do the floor upstairs from new.