the difference is really advanced features and speed of rendering. The good news is there are tons of advanced features in Liquid that make it much faster to do True Pro style Non Linear editing. If all you are doing is cuts and a few dissolves and you want to take that out to DVD, then you may be happy with Studio.
The titler is better in Edition, but having edition, I really want Title Deko Pro even over Title Deko.
If you are not sure and you are worried about spending the money, there are upgrade paths. Both packages are really good buys. The issue is not really quality, although, you do have more export paramaters in Liquid.
If you own other NLEs, there is also a discount on getting Liquid which definetly makes it worth the while. Give us a shout if you need more help.
We do sell both, you can give me a shout anytime