I was surfing around over on ADVrider and found the following thread where the developer is asking for input on his new web based trip planner. I played with it and found it to be much more intuitive than Basecamp. You can plan your route and then import it into Basecamp to transfer to your garmin device.
Disclaimer: I have no affiliation with the developer.
Disclaimer #2: I've only played with it and transferred into Basecamp. I have not yet transferred to device and actually taken a ride (have I told anyone I'm really tired of this winter?)
I have sent him a PM and invited to post over here so I may be overstepping.
Here's a link to his site