I've been thinking about this some more.
Ds came out of school at beginning of Y5 and he was quite an emotional mess to begin with. I didn't feel, in his particular case, that unschooling would be be of use to him because he's poorly motivated at the best of times and I didn't want him to get the impression that HE was about lazing around and doing nothing 
, so we started work more or less straight away but at a very low level. I was also being mildly threatened by the LEA that I might get a call from Child Protection because of an answer I'd given on their supposedly optional questionnaire (long story) so I kind of felt obliged to be producing something.
The only concern I have now is that I didn't spend more time at the very beginning on developing his social and emotional skills (he has AS so is lacking in these areas). However, it could be that I needed two years to work out exactly where those problems lay and how to address them, which is why we're able to put so much more into them now. It might not have worked back then, who can say.
I guess what I'm saying is that you never know for sure (or I don't at least )if you're doing the right thing at the time. I may have made a mistake back then or it might have been exactly the right thing for the circumstances. My experience of HE has been one of peaks and troughs - one week I feel as if I'm getting everything right for ds and others I feel like I haven't a clue and am failing him miserably. But it seems to level out and overall he's doing brilliantly.
The bottom line is that I don't regret anything about home educating and how I've done it. If I have made mistakes I've learned from them and under the circumstances it's the right (indeed, only) option open to ds because of his needs and the support availability in our area. And for me personally, it's been the single most rewarding (if exhausting!) thing I've ever done and I've met some lovely people along the way.