Plain Old Jim,
In my opinion there are several answers to your question due to the many different types of flies that are tied and the different fly fishing styles that are out there.
For instance - I fish nymphs, wet flies and streamers 99% of the time with nothing smaller than maybe a #14. I use and recommend using a Mattarelli whip finisher to finish off the flies. I feel that the whip finisher gives you a more durable fly that will last many fish before getting "chewed" up. I also recommend using head cement for the same reason. If you cut a rope into and wanted to finish off the cut end so it would not fray, you would do a whip finish which would hold up more than a couple half hitches. Please remember this is just my opinion.
If you fish a lot of size #18 and smaller dry/wet flies a couple half hitches may work better than a whip finish. I know that the half hitches would probably give you a smaller head on the fly. You would probably not want to use head cement on the really small flies so that you could keep the cement from getting into the dry fly hackle.
To sum up my opinions on this subject:
For my type of fishing and flies, I use the whip finisher with head cement
I think a whip finish is more durable than a couple half hitches
With really small flies, you could probably get by with a couple half hitches and no head cement
I am like you when it comes to doing the hand whip finish. My hands are just too rough due to they are working hands. I learned to do the hand whip finish for those who feel "you are not a fly tyer unless you know how to do a hand whip finish."
I know that someone with more knowledge on fly tying than myself will be able to give you a better answer and maybe make it clearer to understand.
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Warren
Warren
Fly fishing and fly tying are two things that I do, and when I am doing them, they are the only 2 things I think about. They clear my mind.