Hi, first post. I'm upgrading from a 2009 MacBook to a new Haswell iMac. I know I'm going with the 27" screen but am unsure whether the $1799 or $1999 model is right for me. I'm a graphic designer and regularly have multiple Adobe CS programs open at the same time (Illustrator, Dreamweaver, etc). I also stream video frequently. Seems that the only differences between the two models are processor speed and the graphics card. I don't really know anything about either of these so I'm not sure if the upgrade is worth it in my situation. I'm willing to put up another $200 but I don't want to if I'm not going to see significant boosts. Planning on using this computer for a good five years. Thanks for any advice.