Sure we all hate punctures, but they really do not happen that often. Yes the M plus is the ultimate in protection, but the ride is horrible. You are much faster and you will have much more fun on a more flexible but marginally more fragile tyre. The ordinary Marathon is nicer and still punctures only rarely. The pre 2011 model is nicerthan the current model (and now very cheap to get): for 2011 they have given the ordinary Marathon some of the extra thick rubber of the Plus (they call it greenguard), and I have been testing a set for Schwalbe. I hate the tyre, and have taken it off my bike. Puncture protection of the older model was good enough, and the ride much better.
So what would I use? I think the Panaracer Pasela TG is my personal choice for fast and comfortable in a not too wide size. The Schwalbe Marathon Racer is perhaps not as niceas the Pasela (although the 2012 evolution line model is probably rather better), but more robust than the Pasela.
Compared to the Marathon Plus, a Pasela will get you to your destination some 30-60 minutes earlier each day, compared to which the 15 minutes to fix perhaps one puncture for all of Lejog pales into insignificance. Not to mention the difference in riding pleasure.
Willem