I usually smoke flats and I've never had a dry brisket. What I do...
- Dry rub, cut criss cross pattern in the fatty side
- Smoke at 225°F - 1.5 hours per pound fatty side up
- Put beer in the water tray in my smoker
- baste every hour with a beer/bbq sauce mixture, or spray with apple juice.
- Meat is basiclly done absorbing smoke after 3-4 hours, so if it's cold out I'll wrap it in foil, baste heavily with beer/bbq mix and put in the oven at 225° to finish at 190°
I've done apple juice instead of beer and no bbq sauce, that turns out good too. When I do kobe beef briskets I could pull them apart. Hereford beef (or any other standard breed) stays fairly juicy too.
Sounds like you're drying out.
Your from North Dakota...................