yes they are heavier, but they aren't horrible.
As for wear, I have a set of regular .1.5in marathons with close to 10,000 kms on them and they still look reasonable.
but I'm easy on tires, bikes, cars, you name it
I agree - I like the regular Marathons for many applications. They are good tires and are more cost-effective than much of the competition.
For the OP's purposes, the current 650b regular Marathons are probably too wide - they are listed as 44 mm. In my experience, Schwalbes tend to run a little narrower than what the sidewall says, but probably not 6 mm narrower.
Your mileage will vary. I got only 2200 miles (3500 kms) on a rear Marathon before the belt started showing. It looks like there is a lot of tire left at that point, but the puncture-resistant belt is very thick - 3mm of rubber. By contrast, I have over 11,000 miles (18,000 kms) on a pair of Marathon Almotions and they are still kicking; this is about twice as many miles as any tire I have used in the past. The Almotions have thicker tread (heavier) than the Supremes, so the Supremes will presumably not last this long, but they share the higher-end rubber compounds so I would expect them to outlast (or at least match) regular Marathons and do so with lighter weight and equivalent puncture resistance (puncture rating from the manufacturer). (I am not recommending Almotions to the OP because thay are too wide; in fact, the current model is wider than the old tires that I have and they will no longer fit on my bike.)