We (pitmasterIQ BBQ) switched to a Rebel 28 at the beginning of last season and doubled our awards for the year. It's a great cooker. Firebox walls are 1/2" steel. It may be screwed together, but it's painted after assembly, and the thick paint appears to seal it up well. It allowed us to stop thinking about the cooker so much and focus on perfecting taste and tenderness.
KCBS "pitmasterIQ BBQ" team, www.pitmasterIQ.com, www.digitalpowerandmotion.com