In general, wire bead tyres are heavier than folding. But this doesn't seem to be the case for Schwalbe Mondials: quoted weights in the 26" x 2.0" size are 720 g for wired and 740 for folding. The folding version has more sophisticated puncture protection and would seem to be a bit stronger/more resistant. If going for Mondials I would definitely choose the folding version, the extra 20 g isn't significant.
My experience with 26" tyres is with the 2.0" width, it might not apply to thinner tyres (I suspect that for a given model of tyre, the slimmer versions would be more fragile)
Personally, I prefer the lighter Schwalbe Marathon Supreme with semi-slick tread (quoted weight for 26" x 2.0" size 565g).
I notice easier rolling with Supremes compared to the discontinued Schwalbe Marathon Duremes that came on my Raven Tour. Dureme is a tad heavier than Supreme, and has a more pronounced tread, but has less tread and is lighter than Mondial. I swapped my Duremes to a bike I use for survey work, typically on tracks and paths where the tread might be a bit more useful, rarely more than 60 kms in a day, so the extra rolling resistance matters less.
My own opinion is that the Mondials would only be worth the extra weight/rolling resistance if doing a lot of serious off-road riding, a really long trip in excess of 6,000 kms, or an expedition-type trip far from bike shops where reliability is paramount (deserts, third world countries, etc). On my 3,300 km Spain trip I used Supremes on some fairly rough tracks, with a full load in front and rear panniers.
I don't worry about the relatively high price of the Supremes, so far the front has done over 8,000 kms, the 2 rears 3,400 and 4,700 kms. As a precaution I fitted a new rear tyre before my Spain trip, and risked not carrying a spare, reckoning I could find a 26" tyre fairly easily if needed.
All 3 tyres show little wear. Excluding accidental damage, always possible, and more likely with a light tyre, I reckon Supremes should be good for at least 8,000 kms on the rear, much more on the front.