In the current setup for an enhancement shaman taking EB is that EB is the highest priority spell, thus it then needs to be hardcasted quite often as you can't wait for MSWx5 to make it an instant cast. This is the main complaint from the majority of shamans (including myself) is that with the introduction of EB and the optimal DPS route of even hardcasting LB is that we're becoming more of melee spellcasters and not melee who use spells for damage. Saying that EB is already instant cast, while is technically somewhat correct, is also not reveling the whole truth about that manner, if you're to always wait for MSWx5 for an EB cast you're greatly decreasing your dps due to A) delaying LB usage and B) delaying EB usage while waiting on MSW stacks.
I personally still run with Unleash Fury 90% of the time as I find it a more enjoyable talent than Primal Elementalist, and because of that I find myself hardcasting LB to take advantage of the Unleash Flame buff, but even then I typically only hardcast with 3+ stacks, and even then it's only to really fill gaps, not a fan of hardcasting, but oh well, still really really really enjoying Enh right now.I guess my main issue is I do not Hardcast LB.... I just can't get myself to do it. I normally just refresh ST and drop HST when I have a gap.