Here are some of my experiences with various marathon tyres.
Some of this stuff is pretty obvious, and can be found on the Schwalbe website, but I though I’d include it anyway.
Marathon Classic
I used the wire bead 700x35c version.
+Cheap
+Wear well
-Heavy
-Don’t roll as well as other marathons
Used as commuter/gravel grinder tyre, good deal if you can get them for less than $25 a tyre, but if you got the money I reckon there are better marathons. They last for ages.
Marathon Racer
I used 700x30c folding. One flat while I used them.
+Lite (relative to other marathons)
+Fast
+Corner nicely (relative to Marathon classic)
-Pricey
-Wear quickly compared to other marathons (i.e. ~2000kms and wear was noticeable on the rear)
Used as commuter and road riding tyre. Felt just as fast as other cheap ‘road’ tyres I have used.
Marathon Cross
I used the 700x37c wire bead tyre (think this is all they offer). No flats.
+Cheapish
+Good grip on gravel at low pressue so side knobs come into play
-Slow on the road
-Heavy
-Wore quickly, but I think this was mainly due to me using them on the road.
-Cornering a bit funny on sealed roads due to side knobs.
Used for gravel grinders, gravel road touring and riding lite trails (e.g. Yarra trails). I’d use them again for gravel touring. Rolly has my old set now, ask him how they are faring long term, I probably did ~2000kms on them?
Marathon Supreme
I have Folding 700x35c version. No flats.
+Folding (good as a spare touring)
+lite
+nice round profile corners nicely
+fast compared to marathon classic
-Expensive ($60+)
Best touring tyre I have used, ~3500kms fully loaded on roads, bike paths, gravel roads, my set wearing really well. Usable on gravel roads though not quite as good as the cross in terms of grip, more versatile if you going gravel-road-gravel etc. I would reccommend if you can afford them.