I recently informed my advisor that I was going to head in a new direction, and he reluctantly accepted my decision but added
that the door was open for me to return at any time...In fact, he said that if I changed my mind next month I could come back.

Well, having explored other pastures I am actually starting to think that maybe my phd research was not as miserable, hopeless and uselesss
as I initially thought. Having to look at the alternatives did provide me with some distance and perspective. I mean I really did like my topic I
just could not see how it could lead to a normal job outside of academia and that really worried me. However, having looked at other more logical career
trajectories outside of the phd I realized that nothing else really interests me any more, particularly as I would have to start at the bottom and/or
likely go back to school yet again.

At the same time I wonder whether this time off has really allowed me to put false 'rose coloured' glasses on about the whole PhD thing and this has led to
this gentler reflection.

Has anyone had this same experience?

Afraid I haven't left and gone back as you have. But I've certainly had my ups and downs with how I feel about the PhD. For a year or so I seriously contemplated quitting. Recently though (final few months) I'd gotten more positive and started to wonder about staying in academia after all.....until my husband pointed out that I probably just have a case of "demob happy".
I think there's always a tendency to see the grass as greener wherever you're not, how long have you been away from the phd and how far into it were you?

about two months since I suggeted to my advisor that I was going in a different direction,
but already 5 yrs in and had all data collected,
as did not see future in academia just couldn't imagine how I would finish without seeing light of opportunity
at the end of the tunnel,
lately I've been thinking that perhaps I should finish while exploring related jobs outside of academia,
the prospect of losing all those years is just a little much at times,
K.

I went into my Phd straight after my MA. I struggled towards the end of the MA - basically I had gotten myself into a really negative headspace - writing for days and then waking up and deciding its crap and just deleting it all. Anyhow I started the Phd but started to feel like an imposter and wanted to ge as far away from it as possible. So I took temporary leave with the view of coming back the following year. The time came to contact my sup and I couldn't do it. I thought he would tell me I was a waste of his time etc. So I entered the real world of work. I really enjoyed it and got my self confidence back and started to think abot heading back into phd land. I contacted my sup and they said theyd be glad to have me. I was still extremely nervous and got myself into a bit of state but decided to just give it a go. I had been working on stuff for a few weeks before starting again - really just notes as I write as I read. I also gave him a rewritten conceptual model. I thought it would look good to give him something and so sent it to him. He thought it was a very positive start - even though it was a frist draft he said it was extremely well structured and well written - so much so that I'm going to be fast-tracked through differentiation.

My point is that just do it. Its better to regret doing something than regret doing nothing at all.