Hi All,
I was torn between buying a Seidio powered solution and an Arkon powered mount for my Dell Axim X50. After reading a few reviews, I bought an Arkon CM820 powered GPS mount.
http://www.arkon.com/gpsmount.html
They now have the date serial cable thats included. This wasnt the case before. They also convinced me with a $10.00 off discount for mentioning "AximSite". After a few days of driving around I have had no problems with the mount and the spacemachine software. The amplified speaker sounds good. FYI The discount seems to only apply if you order online and mention it in the special instructions area after checking out. The discount applies to all Arkon Axim powered mounts. I hope this helps.