As a newcomer to the tarsnap family (started using a month ago)- I completely agree - I use Dropbox, Super Duper, Arq, Crashplan for various types of backup scenarios - but the tools that I use to snapshot my ultra critical (all Customer content - code, scripts, visio diagrams, network configs, site/RF surveys) 677 MB "customers" folder is tarsnap. It really is as simple as:
Even more tremendously wonderful - I deposited $20.00 a month ago, and I currently have a remaining balance of $19.826571509446676694.
I.E. Tarsnap charges me 0.173428490553323306/month to backup/snapshot all of the content I've created in the previous 2 1/2 years.
(Note - Tarsnap users so many sigifnicant digits, that OS X calc, Excel, and Python all gave me three different answers for 20-19.826571509446676694.
I had to check by hand, and use the Python "decimal" module to get the "correct" answer of 0.173428490553323306.