I have a 12" SCMS, and yes, they sure spew. One of the best and cheapest
designs I've seen was in one of the WW mags.... Essentially, you build a
frame out of PVC pipe and elbows to hold open a BIG plastic garbage bag
behind the business end of the chop saw. The design mimics some of the
wooden catch-alls shown in the links on these other posts and it seems like
it would work purdy darn well. The bag is opened enough to catch dust when
you're making miter cuts to either side.
I have a Bosch unit and love it... I've only had it a bit more than a month
and was surprised as hell last week when I actually found some sawdust in
the dustbag! Who knew??
Anyway, hope this helps - I've had the DW that you've got and I loved it