Ram works better in pairs.
I run adobe master collection CS4 on my mini, and it works great. All your standar design/web programs work completely fine on the mini.
I can tell you that if you are going to be doing video editing or working with 300 or 600dpi indesign/photoshop/print files, you will probably want to shoot for the sky with 8gb. Might as well. I am going to upgrade to 8gb. Having worked with the mini in these programs, it seems like 4gb would be good, but 8gb would be extremely comfortable and kushy.
Multi-tasking - I have had indesign, web browsing, flash players playing music, itunes, other programs, switching around in spaces and I have not had any lagging.
Video is a whole different story. I myself have played around a little with after effects and premiere, and I have not noticed any real slow downs, but due to the processor speed; doing a ram preview will take a bit longer than say a 24"imac (obviously). But I have yet to open up some old after effects projects that were fairly big and really get down and dirty with AE and Pr. For people like myself who do AE and Pr amateurly and as a hobby, it works fine. Anyone doing light to maybe even mid video editing would be fine, if you add a some patience. One could also bring up the fact that professionals some years ago would be using mobile setups with macbooks that had the same stats as the mini.
My personal opinion and summary - For myself, I got the mini because it was what I could afford being a student and all, and I had done a ton of research on it before I bought it to know that I wasn't getting a bum deal either. I am a graphic/web student as well, and it performs above my needs. Course I also have an issue with imacs/upgrading, but that's another story. I'm also not trying to sell anyone on anything. Just giving my experience. All depends on your needs, and budget. Just know that for what you are doing, you should be plenty comfortable with the mini if that's where you want to go.
Right now I'm just a learning student, but anyone trying to find information on the subject of testing & demonstrating adobe/master collection programs and tasks on the mini can feel free to message me with any questions or requests. When I was searching for a mini/mac, it was quite hard to find info on the subject, so I would be more than happy to be of help.
