I have an offset as well as a water smoker (Weber WSM) that has been used with and without the waterpan.

Can't really tell a dif in the finished product between using the water pan vs. not.

The offset definately is more traditional and imparts a different flavor than the vertical jobs.

Buy a Weber WSM. I load mine up in the morning before work and come home to a great meal at the end of the day.No tending whatsoever.The trick is to replace the Weber water pan with a Brinkmann charcoal pan and use it for water. About twice the capacity.