There is an official referral thread here:
http://androidforums.com/android-applications/68894-dropbox-referral-thread-only-post-them-here.html
As for the OP's question. The good is that it can run on most systems, and it's very low maintenance. You install the dropbox program on your computer and it assigns a dropbox folder and any files you "drop" into it or change within it gets automatically sync'd with all the other computers running the dropbox program and a copy is sync'd online. The bad is that it doesn't sync with handheld devices. From your android phone the app lets you can access all the latest updated files (and download to your device is you choose) but it doesn't sync with a folder on your device to the files on your other systems. Also you from your device you can only upload media or text files. Another negative is that you only get 2gb at first and have to give out referrals to get increments of 256kb per referral or purchase extra space. So unless you pay for the extra capacity, it's really mostly good for sync'ing/backing up just your important files, sharing files, or replacing usb thumb drives.