[ghshephard]

Always two (2) Linux instances (One CentOS and One Ubuntu), and almost always 4 OpenBSD images (for networking simulations). The VMware instances don't really seem to cause any foreground processing pauses (unlike the Craptastic VMware Workstation on my MacBook Pro + WIndows XP which leaves me in constant jerk-spinning beachball state. Grr...) - Runs super smoothly.

I do all my interactive work on a (Circa 2010) Macbook Air - the Windows XP system is for Visio, Dynamips, Vmware Workstation, PowerPoint, Visio, Microsoft Word, and Outlook+Lookout (I have 10 years of Exchange PST's cached on that box) - I don't think a faster system would give me much more than 10% improvement in performance - because I'm never really CPU bound on that box. And, honestly, I spend maybe an hour a day on it - the other seven I spend on my MacBook Air. I just don't see any justification to upgrade it. It gets the job done, and it's fast enough.

With all that said - the upgrade from my 2010 MacBook Pro to my SSD based 2010 MacBook Air was an awesome performance jump. Totally worth it. CPUs may not make much of a difference but WOW, do SSDs in a MacBook rock your world!