For a more tender brisket, next time either:
leave it on the smoker until the internal temp hits 203, pull it and let rest for 30 minutes covered in foil, not wrapped, before slicing, or
pull it at 185-190, wrap tightly in foil, wrap in towel and put it in a cooler for a 2-3 hours.
Both ways work for me for an awesome brisket. A lot times people get in a hurry trying to meet a specific eating time and either crank up the temp or pull it off early. No brisket is the same and there is no precise time for cooking one. It will take as long it takes. You can't rush it. I would rather put on to early than to late.
And buy prime briskets, not choice. I usually get mine at Costco.