In a comment on the recent EE Times article, POET Technologies published a nice summary regarding performance, density, and costs of their chips. Here's my blog post to make this more accessible to German readers:
http://rainerklute.wordpress.com/2014/09/17/geschwindigkeit-packungsdichte-und-kosten-von-poet-chips/
English readers will find their usual English abstract and the link to the Google-translated version, but you could as well read the comment on EE Times directly. And, by the way, it has been published in this forum already, so why am I writing this …