I just finished a cutter using SD. I wanted to weigh out the opinion about the carbs being crucial as well as water retention issues.
beginning weight 183
Ending weight 186
weight 1 week post 183
BF% before 11% after 8% (3 point measurement)
SD @ 30mg
calories (cyclic from 1400 - 2300) 40/40/20 (except on low carb days)
cardio - moderate intensity on cross trainer 30 minutes each day
lifting - two heavy compound movements with rest (3 sets each)....then circuit training and/or drop sets (another 4-6 movements 3 sets each) 5 day split
I'm an ecto/meso. I retain a lot of water weight when bulking (I like wet stacks) so I know what water retention is like. I can easily drop 8 pounds of water post cycle when using 4AD or M14ADD. I bloat easily and lose muscle easily if I'm not careful during a cut.
So here are my personal opinion/observations.
My strength stayed up more than it would normally on a cutting cycle. Obviously it wasn't on par with a bulk, but actually pretty close. I can gage this from my workout partner because we are pretty close in strength. He out-repped me on most lifts but not by much (he weighs in at 235

)
Water retention was definitely there. I looked tremendously better in the AM than in the PM. Although this is normal when you get lean, it was much more apparent to me this time for some reason. The water loss at night was seemingly ALL subcutaneous.
I didn't feel the "crazy strength" that I did the first time that I used SD. Although that time I was stacking it with 1-T/4AD so it's hard to compare.
I definitely had massive pumps (to the point of cutting some workouts short or switching muscle groups) again. I wasn't feeling the pumps until the 2.5 week mark though whereas the first time I felt them at the end of the first week.
I'm not sure what else to say about it. I think that stacking this with something like M4OHN or MDHT and/or 1,4AD would be a great Summer stack. I don't think that you have to worry TOO much about water retention...but it is there to some degree. But you definitely look "blown" even in a calorie deficit and low carbs.