I started using Polywork recently and was pleasantly surprised by the deep well of opportunities listed here. It was nice to see a site for someone like me -- I dont just have a job, i'm also on boards, i'm an investor, I want to participate in community projects. Polywork was great at helping surface interesting opportunities for active people looking to get involved and grow themselves across many dimensions.
Everything that's wrong with LinkedIn, is done right on Polywork. I have a huge following on LinkedIn but I can NOT wait until we all move over. The network is welcoming, the features match people's professional lives much better, and it simply is an all-round improvement from design to functionality.