I can see this as being great for inexperienced founders looking at getting funding for their first stab at being an entrepreneur. However, any founders that are talented and have worked as an engineer at at least one moderately or highly successful company should be able to raise money on much better terms. Giving up 15% for $150k seems pretty steep, especially when the investor in question is spread so thin. Money and maybe occasional introductions are going to be pretty much the only forms of involvement that the investor could realistically invest in you.