Re: Fly line leader connection
I will just say this. If your fly line already has the loop, I'd go with a perfection knot b/c it is MUCH easier to tie stream-side should you ever have to retie. Plus, many prepackaged tapered leaders come with the loop already tied, simply join the two loops together and there you are. I never end up with line through the guides anyway, but I can see how that would be a drawback. I'd try both and see how it goes, just my opinion.
A bad day hunting rabbits beats a good day of anything else!