Here is the truth. Headspace 2 is more complicated and powerful. However, it is marginally more powerful and greatly more complicated than the WordPress All-in-One-Seo plugin. So it is really a cost benefit choice.  For me the marginal benefit and great time I could spend getting up to speed on the wordpress headspace 2 plugin or working around some of the issues now, I could be exporing other ways to SEO my wordpress blogs.

Further at this juncture headspace 2 has some conflict problems with other plugins. All-in-one-SEO plugin not as many.

Further, WordPress is pretty good SEO ed out of the box. Only a few twicks are needed. More importance is the fundementals of SEO.

Therefore, All-in-One-SEO is better because of the ease of use. I am staying with this until I see a huge difference in those using Headspace 2 plugin for WordPress that can not be explained by link growth.