I think my main concern about spreading out a PPL wasn't so much the flying - though I spread out hang-gliding lessons and that was very much a case of 2 steps forward, one step back.
My worry was that I wouldn't be able to concentrate on my career properly if I was thinking about flying and the PPL exams all the time. I had the opportunity to take a little time out and get it all done and dusted, and whilst I continue to learn and read pprune etc... it's overall much less intrusive when you've already got that qualification.