Hi,
You mentioned that you want to learn linux. Thing is, Mint/Ubuntu run are based on Debian Linux (Correct me folks if I am wrong here). Suse is based on its own version. If you want to learn the version of Linux thats most used commercially, I would suggest you try Scientific Linux 6. Its based on Red Hat Linux minus the proprietory software. Dont think that it will have a lot of scientific stuff or something like that....Just that its developed by Fermi lab so thats the name they have given it. Google for Scientific Linux 6 and you'll know what I am talking about. I tried installing it and it worked fine...I do not have an XPS but am planning to by one [from a long long time....about time I get it hehe] Say if you are learning linux because you aim to be an admin, there are couple of differences in these versions..for example, any Debian based version, if you want to update some software, you would have to run
#aptget <package_name>
Same thing in Red Hat Linux would be
#rpm -ivh <package_name>
Or
# yum install <package_name>
So choose your OS accordingly. If you intend to learn linux just for knowledge, then thats a different thing...any version will do..
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I hope more experienced linux guys here would correct me. I am just trying to help as much as I can.