Yes, I have tried the Slimserver handheld skin.
I had it loaded on the PDA whae I first went over to Mike's We tried it out for a bit and then we switched to TelCanto.
We both preferred the TelCanto interface. It was far faster to respond. The sub-directories were easier to access.
The volume control gave greater control of the steps and it has a mute button. You could control volume by using the thumbpad on the bottom of the PDA.
I find the TelCanto to just be more user friendly.
It is $51.00 but It do feel it is worth it for the time that went into coming up with the interface.
BTW the PDA I am using it on is a Dell X-50. It should work just fine with a Dell X3i wireless. These should be able to be found for under $100.00 on E-Bay
I will bring it again for out get togeter next weekend so others can try out both programs and see what they like.
TelCanto is available to try for 30 days for free. I do suggest you give it a try. I do think you will end up buying it.