Hey bro, glad that things are working out for you after all with the 260! That is a great machine IMO, and I was sure you'd get the results you were after with a little investigation and adjusting.
Not many decks can process a tall cut off of crabgrass or clover, and worst of all is what many call crabgrass that is actually in reality goosegrass. It looks very similar to crabgrqass, but it is the bright green stuff that is always wet even duringa drought. Look at the links and you'll see what I mean. That stuff is nasty to cut, and ALWAYS clumps no matter what when the lawn has much of it in it.