in my opinion pure broad match is the better as it gives you more traffic.

If you have more traffic per keyword this means a rapid developing of your Quality Score and consequently a lower actual cpc.

Your objective in AdWords is always high traffic and a high ROI (low bid) isn't it? So use broad match.

Forget mixes: broad+phrase+exact of the same keyword this will split your Quality Score cell and statistics into 3 places - if this is really useful, AdWords team would created a tool for that months ago.

When using broad match you need to add tons of negative keywords to your campaign or it will not work as expected.