I get by fairly easily on 4GB of RAM with my 2011/2012 model MBP (bought it last January) using Nik, Lightroom, and Photoshop. Yeah, it isn't instantaneous with everything, but it can handle most intense processing methods within a minute or two for really heavy stuff like Photoshop merging, panos, 360s, etc. I love having a laptop because it gives me something to do on flights (hey, cleaning out my Lightroom library might be a good task on my 7 hour flight to Cali later this year!) that helps pass the time quickly, assuming I don't fall asleep first. I have thought about picking up an iMac/Mac Mini or building a fairly cheap desktop, but my MBP serves all my needs just fine for now.