I have been using a 15" Core i5 mid 2010 MBP for a while. I have 8Gb of RAM and it works perfectly. I use it for fairly big/complex models for SketchUp and Podium. It's fast enough for me, and I have an 8 core Mac Pro in the office. Considering what desktop machines some people have (and there are lots of people still using XP) this machine is plenty fast enough for serious SketchUp work and rendering. Before I had my current machine, I had the old model 15" Core 2 Duo MBP with the Santa Rosa Chipset and 4Gb of RAM. I didn't have a problem with that either. Any decent spec MBP ought to be better than any Desktop PC running XP 32 bit. The DVD writer in my old machine failed 5 times over the space of 3 years, and just before my AppleCare warranty expired, Apple replaced the machine for free with a brand new model of the latest spec. AppleCare is awesome! I would advise anyone who buys an Apple machine to budget for this if remotely possible. If you don't live close to an Apple store, ring them up and they'll send a courier to collect your machine, and return it around 3 days later. They'll even supply a box I haven't seen any reports of MacBook Air machines with SketchUp. I would have thought it would be fine for smaller models, but for rendering or very complex models, the 15" Pro model is the best balance between power and portability - IMO.