I did a couple corned beef briskets on the WSM and they came out great.
I bought a small point (2.5lb) and what was marked as a flat (4lb), both supermarket cryos that are typical this time of year. When I opened the flat, it had the normal flat portion with a second chunk of meat above it separated by a thick band of fat. I'm not sure what this cut is called.
Anyway, I covered them in water on Thursday night, changed the water on Friday morning and changed the water a second time after work at about 5:30. At about 7:30, I took them out of the water and set them to dry on a cooling rack. I got the WSM-18" going with a full load. Once up to temp, I applied a thin layer of yellow mustard to the briskets and rubbed them liberally with coarse black pepper and dusted them with some ground coriander. At 9:15pm, they went on the smoker. I checked the temps a couple more times that night, the last at almost 2am. It was 250 +/-10 degrees each time, right where I wanted it.
I've had some bad experiences with overnight cooks so when I woke up and checked the meat at 8am, I was a little worried. Luckily, the rack temp was about 150 and fallings, so I got to them just in time. For some reason, a lot of the larger pieces of charcoal never caught and the fire went out quicker than expected.
These are about the best things to come off my smoker yet. The bark is incredible and the meat is just-right tender without falling apart. I probably could have skipped the second and third water soaks since I think they could have been saltier. All in all, really, really good brisket/pastrami and I'm thinking of doing it again soon.