Posted: March 30
It's really simple. If you've played/own SC1 and/or FA, this game will probably disappoint you. In general, lots of options have been taken out which were present in the predecessors, including diversity and lots of tactical features, especially the latter being very important aspect of RTS genre.
However, this has been happening with most of (RTS, but also others as well) games recently. This game fits into this new category of "next-gen" games. The UI and Graphics have been updated (although in SC2 it isn't as fake flashy as in other new games), so it appeals to new and probably young players (who otherwise lose their attention if they aren't surprised in the first few seconds of seeing a new game, and the very first thing you see in a game is how it looks like). Also, it has been simplified a lot (or, I think it was both partly, it wasn't really finished yet), but that again can have its positive effects, like new players get into it faster and you can convince friends to play it easier.
So for situations where you've got some time for a long battle, together with other RTS-dedicated friends, SC1 and FA fits better.
However, especially if you haven't (yet) played the previous ones in the series, this game can really be awesome and fun to play. The largest maps in the game, while far from the size of SC1's and FA's 81x81km games where you really wish you had some Homeworld hyperspace modules, they still give some lengthy plays and tactical options. The smaller maps are good for quick plays, when you don't have that much time.
You've still got control of exlusions of what can't be built in Skirmish/MP and the game can be modded quite easily (although not many mods are made), so for some casual battles you can change things slightly (like I find it relaxing to sometimes play without nukes and/or air units). Also, some mods are actually quite good, and some bring back some SC1/FA features.
So to conclude, if you want lots of tactics, slow(er) gameplay, grand scale and planning, you'll probably like SC1 and FA better. However, if you want some quick matches, easier play/calmer learning curve, or want some friends to join you quickly who might not be into RTS games that much, SC2 is a quite nice game to play.
I'd certainly recommend buying it in a sale, it really is worth the price when it's reduced like that.
Oh, and don't forget to buy the Infinite War DLC, it is a must for the game!