I've had them both. The medium fits a ton and I prefer that for everyday use (commuting and bike camping (but I don't do a lot of heavy duty grocery getting or any errands like that). Nice thing is that even for an S240 you can get a lot in there and bulge it out for some extra room. All depends on what else you have for storage. I find a medium saddlesack with a front shopsack--or even better some low rider panniers (I use the har ones)--really balance out the weight, that way you're not too tempted to put too much in the large and overload it. My hunqapillar gets a lot of shimmy from overloading a rear saddlesack.
Or you can take my route which is to buy them both, find out which one you like, then sell the other one at a slight loss. I find Rivendell products hold a good amount of value especially if barely used. I now look at fancy bike and bike part purchases as a rental fee with a large deposit ;) -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at https://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.