I will start off by saying that Northern Brewer did a great job. Good price, fast shipping, and packaged well. Yeast arrived cool and viable. Thank you NB. Now the Yeast. I purchased 3 Wyeast 4184 slap packs specifically for high SG sweet mead. All 3 packs had different expiration dates and all appeared to be in good condition. First mead that I made with the oldest pack was a Concord Grape Pyment. Slap pack never really inflated, fermentation was very slow, I had to add energizer, and appeared to be very temp sensitive even within the listed temps. It did ferment through to an FG of 1.050 and an approx ABV of 12%.Second pack was for a Fuji Cyser; slap pack infalted completely, slow start, fermented out to 1.000 with an approx ABV of 15%. It was very dry and not what I was looking for. The third pack was for a sweet dessert mead on a Staggered feed schedule. This was the newest pack. It inflated completely and when pitched it took off like a rocket. It fermented out to 1.050 as well and I managed an approx. ABV of 16%. These yeast were all over the place. As others have stated, it is not only finicky but also unpredictable. At least they all fermented. That said, definitely use a Nutrient schedule, ferment in the upper middle suggested temp range, monitor closely, and most important; be patient. I will buy this yeast again, but I can only recommend it for brewers with some experience.