I personally feel drafting, perfect presenting is more important than its frequency. Also sharing on social networks plays a major role nowadays in letting the outside world know about it. So frequency is not the primary aspect for any kind of blogs.
I feel blogspot is good for less investment, while for easy access to the entire site (coding part), wordpress is greatly helpful!
However, both are good when we do it to our best. People still believe blogspot works better since it is owned by Google.
People nowadays concentrating less on Guest blogging as Google Matt Cutts have said if it their only activity for SEO, then they will be penalized. However, I personally fee somehow guest blogging helps because, our links in the author bio also plays a huge role.