Hello. Im a mechanical engineering student and I'm going to be buying a laptop primarily for solid works and auto cad use. I have had a MacBook pro since high school and that is simply not acceptable for autcad and solid works. Autocad is slow and solidworks isn't even compatible. I have decided to get a thinkpad and am particularly interested in the p53 series because of the full size keyboard. My question is that should I get a p53 or a p53s with an upgraded ram to 16gb for slightly less. Also does the p53s also have the multiple hard drives slots like the p53 does? I know it does have the extra DIMM slot which I appreciate. I couldn't care less about form or battery life and I know that's a big difference between the two. I am more consered that the p53s will get hot under stress. I am astounded how little info about this is on the internet. If anyone else on here is a solid works user and uses a thinkpad to do so I would love to hear your recommendations. I plan on using it mostly for autocad and solid works applications.