When I decided to move my blog, I didn’t expect that it will require such effort. I found a post http://geekswithblogs.net/jakob/archive/2015/12/07/this-blog-is-moving.aspx that refer to tools stored on codePlex http://gwbtowp.codeplex.com/  (now it’s moved to https://github.com/MrHinsh/gwb-to-wordpress)
I downloaded the code  and had to fix a few errors, related to my data. Also I wanted to move my articles that in GeeksWithBlogs are stored separately from normal posts.The final code changes I’ve published at github fork https://github.com/MNF/gwb-to-wordpress.
I expected that import to WordPress will be straightforward.I found a few articles about  import plugins, e.g. http://nixmash.com/on-wordpress/importing-a-big-honkin-blogml-xml-file-into-wordpress/, but then realized that custom plugins not supported in Wordpress.com.
For Wordpress.com I found 2 tools blogmigrator (https://github.com/Dillie-O/blogmigrator ) and  BlogML.Helper.exe (http://blogs.biztalk360.com/migrating-your-blog-from-any-blogml-based-platform-to-wordpress-2)
blogmigrator has less steps to do, and I tried it first. Also I have to do some changes to improve error handling(the changes are incorporated in https://github.com/Dillie-O/blogmigrator) and finally I’ve got my blog imported. But comments were not included. I checked the code and found that comments were not supported in interface that the tool is using.
BlogML.Helper supported comments, but due to bug only one comment per post. I fixed the bug as well as insufficient error logging and finally was able to import my blog to WordPress.
Thanks to the developers who shared their code to help me to finish this work.
By the way import to WordPress also has a few problems, that I had to report to support forum, but they were either resolved or had some workarounds.
Michael Freidgeim's Blog 