It is only over the last couple of years that I have actively and objectively criticised my own improvisation - the many hundreds of recordings of it that is. It isn't something I would advise a beginning improviser, or one unsure of his direction to do at all, and I certainly never do it during the actual playing. I suppose listening regularly to the large body of one's own improvisation might appear morbidly introspective to others. However, considering the amount of time most people my age squander boozing and watching inanities on television, I scarcely think it matters.
If certain bits of musical sound were not in some sense "better" than others, at least to me, then I would be 100% satisfied as long as any sound was produced. I am certainly not so inclined. Obviously there has to be more to it than that; implicit standards do exist in my brain even if I choose to ignore them - a futile course I have tried in the past. The "puzzle", if you like to call it that, is to objectively understand which properties stand out and try to understand why. Then presumably I can guide the overall evolution at a meta-level over whatever time I have left. What amazes me so far is just how ferociously complicated and convoluted this is.