Use the knot that you are comforatble tying. Most flyfishermen will NEVER apply more than 8lbs of pressure on their tippet. In fact, the upper end of fly reels seldom go above 10lbs of drag. If you use 15lb tippet, you are not applying more than 60 per cent of the static break strength of that tippet. The exception is the jerk test. If you have the telltale curly Q at the tag end of the break, then the knot slipped. Not good. Experienced flyfishermen can apply more pressure, but they are the exception.
Here is an approach that provides a non-slip knot with a doubled main line thru the hook eye, like a palomar, but with a loop. Double over the tippet material, make an overhand knot in the doubled line, pass the doubled line thru the hook eye, back thru the overhand knot, wrap around the doubled standing line (3-5 times), back thru the overhand knot. Pull tag end to secure the barrel wraps against the overhand knot.
I tried this several times today. Looks good, but I have no idea of its breaking strength. The advantage I see to this knot is that it doubles the line thru the hook eye, and conceivably would provide added security.