last night i hooked up the dust collection port on my kreg jig and i was amazed at the results. without the dust collector the jig makes a huge mess, the shaving ports get clogged up and the drill bit struggles to make the cuts. with the collector hooked up theres absolutely no mess at all and the drill bit goes right through like butter.
my shop vac has a 2-1/2" hose and the kreg port is much smaller and since i didnt have an adapter i had to figure out a way to hook it up. i ended up using some pvc pipe and a tapered attachment i had and taped it all together. its ugly but it works fine
if you have an older kreg jig you should do yourself a favor and get the vacuum attachment for it!