Don, I actually agree with most if not all your points..
In our dojo we sometimes before or after class we do a bit of "practical applications", basically, just fooling around while waiting for everyone to arrive. in a way, it's a bit of like sparing.. Its just not part of the curriculum.
Its just that whenever I "win" its just that i get the feeling its because im stronger or bigger than my partner, and when I lose, its because my partner is stronger or bigger than me..
It makes it hard for me to evaluate the benefits of sparing when my own experience of it has yet to show me any..
Or they are there, I haven't yet discovered them..
What is the problem with concept of winning in sparring?
Does it not convey that you have been better than the opposition, and that precisely how you know you have been successful in the application of you technique.
Sure you can use euphemism like at that time it worked well or yeah that technique was successful, but albeit being periphrases and not euphemism, they do carry the same meaning, just more PC.
A sparing session is made of plenty of victories, plenty of defeats and hopefully not that many double kill or status quo.
I think you need to recognise them as defeat or victories in order to get the lessons as to why and what lead you there because that is what we try get out of sparring.
After I spar, I usually have a chat with the guy to see how he saw it from is side. What mistake he exploited what opening I left.
It is good as well to have a 3rd party (that is knowledgeable) looking and have his/her impression.
As Don mentioned, this is kilometres away from competition. Sparing is a really good tool to make you understand what is need to a given technique to be successful, especially when you fail.
Next time you do it, try to see where your uke stops you and take advantage of the situation and take from there.
If I am so bold as to add to Ron advices, May be you do have the technique in front of you anymore, or the bit you are working on is not longer isolated or you have weakened you position by over stretching, may be is moving in such way that you should change technique and so on.
those are thing you can then take to your from pratice.