Whats a body like a Canon XT like with a heavy lens like the EF 24-105mm f/4.0L IS USM Zoom on a tripod? or even just holding it? I've help the XT with a kit lens but to me it seems like it would be a little front heavey with a better lens. WHats it feel like with the EF 17-40mm F/4.0L lens as well? Im trying to decide between the XT/XTI or a seconf hand 20D.