I also brought a iRobot Braava Jet 250 a month or so ago.
After initial reservations, around it basically just pushing a wet cloth around which is why I dithered about it for several months, I am actually very pleased it with.
It needs a bit more in terms of initial set up (floors need to be vacuumed/swept first - I just send the robovac round), liquid & cleaning pad added, placed appropriately etc. But almost nothing at the end (eject pad, put battery back into charger, put in cupboard) compared to emptying the robovac. So that probably evens out.
I can't be bothered mopping the floors (have a steam mop) so they probably got done once a month on average, maybe slightly more in winter and less in summer.
With the robomop I set it off twice a week in the kitchen & conservatory so while it might not be quite as good a clean (I'd change the steam mop pad 3 times in this space whereas the robomop just has the 1 pad) it is getting it a lot more often.
I'll then charge the battery and set it off in the utility (only about 3m x 0.8m floor space) later.
While I'm working at home this is working really well. I do it on Monday and Friday mornings. Not sure what I'll do when we are back but the office. I don't work Fridays so that's okay, but it does need the floor vacuuming first (especially as DP's dog which is here over the weekend moults a lot, and sleeps in the kitchen so can't leave the robovac in there overnight) and I don't know if there will be time for that before I leave. Maybe it will be a case of putting the robovac on as soon as I'm up so it's done by the time I'm ready to leave.