It's a difficult thing, finding boots that fit. Like many others, I have one "odd" foot. I think it's the left one but it could be the right. One of them's a bit out of kilter with the other at any rate. So I'm well used to playing around with the fit;adjusting laces, one sock or two and so on.
The 390's need very little in the way of adjustment and that's a minor miracle in itself. I've been wearing them at work over the last week and they've been fine. At times, I forgot I was wearing them and that's always a good sign.
I've got high hopes for these over the coming months but I'll reserve judgement until I've put some serious miles on them. Anyway, Chris Townsend likes them so they can't be that bad :o)