I think it's very important to try out most/all of them to find out what you want. After a long fight with the MS Ergo 4000 after supplies of the original MS Natural dried up, I decided to try out "standard" mechanical keyboards. My first was an XArmor brown, but I tried out my brother's Topre and Filco Blue keyboards shortly afterwards. I loved the blues--and a blue (though XArmor) was my next purchase. After several weeks of real world use using a brown at work and a blue at home, I decided that I preferred the lighter browns over the blues, so I bought a Filco brown. However, several months into my mech keyboard experiment, I determined that bottoming out was just the way I type, and that the tactile feedback on the browns was doing nothing other than adding an unpleasant roughness to the stroke. Given that, I bought a Filco red next. Wow, the smooth keystroke easily made it my favorite of all 4 in short order. I've subsequently purchased another red--the Leopold, and I'm not yet sure if I like it as well as the Filco. It somehow seems to have a "softer" keyfeel and I'm not sure I like it as well, but I've only had it two days.
I fully intend on trying the blacks as well at some point, but I don't hold much hope for liking them given my reason for moving on from the blues. The good news is that I use a lot of systems, so I've been able to find places to put all of them, in order of preference and usage.
In short: I went from browns to blues to reds. I prefer reds, browns, then blues. If you have the means, give multiple switches extended tryouts, as it may surprise you what you end up liking best.
