i am looking at replacing my surly pacer frame for a rear rack compatible frame. the casseroll and crosscheck seem good contenders. however i am not sure about how (or if) each bike flexes under pannier load. i ask this because running a carradice sqr tour seat post bag on the pacer made me feel like the frame was going to snap. yet running it on my thicker tubed, compact geo on-one il pompino there are no such issues. so i am aware that dangling bits from bikes is not always as nice as it seems...my feeling is that the salsa would be more stiff than the crosscheck, though i could be wrong...it also might be the case that because panniers are lower than the carradice post bags the sway and flex issues are minimised anyways. never had panniers so i don't know.
oh, anyone with size 46 feet found a prob with foot-pannier strike on these models...i don;t want to get a long haul trucker to completely tule that out, too heavy i fear...