So, it seems I share something in common with Margaret from 'The Apprentice' (UK version with Sir Alan Sugar). She's quit the series to concentrate on her PhD in papyrology. I'm carefully avoiding novel writing until I've finished mine. That said, I do occasionally plan things out, so by the time I'm ready to get stuck in again, I'll know exactly what I'm doing.
That, I think, is probably one of the important things with any sort of fiction. There's a temptation to just write it, or to get the plan done quickly and then get on with it. It's a temptation I've given into more often than not, only to have to do some serious reworking. I'm beginning to suspect though that the best results come when you live with ideas for a little while, giving them time to fully develop.
And the best part is that it's doing the PhD some good. I'm still going round re-writing, but I'm not getting masses of comments back now. My supervisor even mentioned getting in touch with likely examiners in our last meeting, so it can't be that far now.