This is the link to the Apple on-line store Lion USB flash drive which I am not advocating you buy, just that it gives some of the Lion requirements and goodies it does. The Lion download is only $29 from the app store, but if you want a "hard" backup the flash drive is one way of doing that. There are other ways that are less expensive if you are interested we can talk about those later.
Frankly, iCloud is a big selling point to people. I have Lion and really like it, but if you look around on here there are others that don't feel the same way. For my uses it is fast and powerful. But I also bought a new MacBook Pro with it installed and got 8 GB ram to make sure it has plenty of room to work. Plus added a 2 TB external hard drive for Time Machine backups and additional work space.
There is a down side to Lion, it no longer supports Rosetta and, thus, will not run any of the older PPC compatible software. If you use software like MS Office you will have to get version 2011 for it to run under Lion.
With the latest Mac OS X, Lion, you know you will have compatibility with the latest Apple software for years to come. That is, it will outlive the other operating system versions.
Hope this gives you some things to think about.