i really like the Pro-stripe and especially Yellow Jacket; i prefer his visibility lines of color so haven't tried Pro-spec. Some of the guys seem to have found Yellow Jacket to be a lil'skinny and slippery; i seemed to not notice after a day or so of wear.
BluSt. is supposedly made for foot locking, and i don't really do that, so can't weigh that in.
i try to look at 10:1 safety factors, on a 6k line that gives me 600# of load before bending that safety rule. i try to eliminate shock loading, unless i can use that force to perform a needed task. Generally, i feel like i grab a 5/8 line or put another leg of support line on the load (either physically a seperate line, or a pulley on the load to apply 2 legs of support from the same line and have more pretightening at the same time) as i approach 600# of load, actually look to do that around 3-500# class, so the extra capacity of the lines becomes marginal, though the confidence is nice. i beleive that 8:1 is more of a standard elsewhere, (some say 4:1!, but not i on synthetic, overhead control say i!!), So even with that i feel that with my 'system' i have ~175# of forgiveness in there on that point.