My younger son is a cardigan lover, so I saw this pattern and said "Christmas present!". Foolish me, I decided on black - good choice for him, but I never did an all black project before. Once I got the hang of the stitch, things moved along, and the instructions were pretty straight forward. I only had one question which customer service clarified for me. It is properly considered intermediate difficulty. But seeing details with black yarn is not like any other color - it is tough. A few specifics
Meeting gauge for the first sweater was a bear. Meeting it for the second sweater (olive green) was much easier, because the green yarn was a bit thinner and definitely softer than the black, even tho it is the same yarn. I find this often - different dyes significantly change the weight and texture of the same yarn. I even notice it when I use a color changing yarn like Mandala, and my work gets thicker and thinner as the color changes. But I digress. MAKE SURE YOU MEET GAUGE, as you are working side to side as opposed to bottom to top. I had to go up a half hook size myself. Interestingly, I bought the same amount of green yarn as I the black. I had much, much more green yarn left over (like 2 extra skeins), and both sweaters are the exact same size. Makes no sense to me.
Do not expect to do this quickly. The HDCSlip stitch is slow going, and it makes up much of the sweater. The hook does not want to pull thru the yo and you have to put a finger on it. Once you get the hang of it, it is not hard. But it is not speed crocheting.
I did flip the sleeves over as I did not think the decorative seam looked good - maybe it was my seaming, but flipping it easily solved the issue.
The sleeves are a little long, and it's hard to tell until you are done. Since you are working side to side, you are kind of stuck unless you want to rip out and start over with a shorter cast on. I could not have my boys try on and measure, as they are surprise gifts.
The pockets at 6inches seemed a little shallow, so I pushed mine to nearly 7 inches, and tacked the corners to the first row of the facing so they did not show.
The material you create is substantial - this is no light weight cardigan. Perfect for my needs, but your mileage may vary.
All in all, I am thrilled with both of them.