In just a few hours we'll be presenting at the Keiretsu Forum meeting in Seattle, and on the afternoon we'll be presenting in Bellevue.
Of all the angel groups, Keiretsu has been hailed as the most effective. To begin with, they are a for-profit organization, which helps on the professionalism side, but the core aspect, IMHO, that makes Keiretsu so different is that the Angels there are very active and really interested in investing, not only listening.
The downside is the long due diligence process of about 9 weeks. This is great to give the angel investors more confidence on their investment, but it is not so great for the entrepreneur, since you are taking angel money (low amounts), but going through a VC-like process.
On the 10,000 foot view, the due diligence might not be a big thing if at the end of it you get out with your round complete (raise all money you wanted). But it can be tough if no one invest.
I'm the Co-founder & CTO of 
