been trying to replace my normal lei shens final orders (2/2 upgrade, so 497ilvl) for a while now, and with work in the way i havent been able to raid normal much this past month (qq tank getting thunderforged primordius trinket). got a spark of zandalar lfr today, and wow, is the proc rate really that aweful (2h frost) ? takes a buttload of time to build the stacks so you cant really line the str buff with anything else, im considering just going back to the lei shens trinket (or 2/2 relic which is probably better than both)
did some tests and it usually takes me around 2 minutes to get to 10stacks, give or take a few seconds. seen streaks of no proccing stacks for up to 20 seconds.