The key elements of offset smokers are size and mass. The objective is to get your meat chamber to 200-225 deg and hold it there for a long time. The smaller offset smokers require A LOT of attention to do it.
You need smaller pieces of wood because the firebox is small, and so the temp doesn't spike when you add it. The low mass of these smokers make them more susceptible to temp changes. And smaller pieces of wood mean more frequent adding. You can figure they'll need attention at least every 30 minutes. It is quite a commitment when doing a 12-hour butt or brisket.
The remedy is a bigger and heavier smoker. Mine is 1/4" steel and weighs 1500 lbs. I had the deck especially built to hold it. But it has a big firebox, (and a big meat chamber). That means bigger pieces of wood. The high mass means less change in temp when I add a piece or 2. I still have to tend to the fire every 45-60 minutes.
You CAN use charcoal for heat and wood for smoke in the smaller smokers, but the result is not the same as all wood.
These are the top 2 makers of real smokers: Klose and Gator.
http://www.bbqpits.com/
http://www.gatorpit.net/
Unless you're prepared to tackle BBQ w/ a commitment and enthusiasm that matches what you have to Audio, I'd suggest you stick w/ the Weber. They're a lot less work, you're already familiar, and they do a good job. I went through 3 Brinkmans before stepping up. I was happy and family/friends were pleased. You can think of the Weber/Brinkman as an AVR, and an offset as separates.