Hi Chris,
Shouldn't be any problem in changing your shoes and in any case it's got to be better than running a marathon in something that's going to cripple your feet.
Your experiences with the Creations are interesting. I had a pair until recently and initially they were really good - superb cushioning and pretty supportive. But they only lasted about 260 miles and towards the end I definitely felt the support was giving way and I was getting quite serious blistering under my arches, which I've never had with any shoe before.
Chucked 'em in the bin and I'm afraid I won't be buying any more - I expect about 500 miles out of a pair of shoes, particularly when they cost 90 quid!
Dave