Disable SELinux on your dev box!
I spent a huge chunk of the weekend trying to figure out how to configure Samba on my Fedora box. I was able to connect and read files, but was not able to write files back. It would create the files, but not allow a write. On the Linux box I was able to open the file and the permissions appeared okay.
I tried to setup FTP as I figured it would be the next easiest way for me to get my cross build files off the machine and onto the Slug. While doing this and running into a similar issue I realized something else must be at play. I looked at the log (dmesg) and was able to use a Google search to find the culprit; SELinux security. Disabled it and Samba works great!
I have Samba running on my slug already so now file transfers are trivial.