RunnerManSam - if it's only your second marathon I'd stick with the usual running shoes. It takes time to build the strength in your feet to cope with lightweights for 26 miles.
I am offically benched. Should be hitting peak mileage around now, but instead I'll be on the exercise bike and doing yoga. Physio says no running, impact or elliptical (among other things) for at least a week till I see him again.
Wish I could DrD, but the fizz has benched me. No running, impact or using the hamstrings for the next week then I can try a run before I see him again on Wednesday. A short one, apparently. I suggested 10 miles. He talked me down to 5.