No heat issue for me, fan running at 2k rpm on normal use.
Never remove battery and just run purely on AC power.
Laptop is different from desktop. The Battery do act as a buffer in case AC voltage spike or else. CPU performance will be regulated and not performing at optimize output when Battery is removed.
Read this:
http://support.apple.com/kb/HT2332

If you really think removing battery is good when connecting AC power, then why did Apple engineers spend so much time scratching their head on designing the new 17inch MBP non-removable battery?

This post has been edited by ahblu3: Mar 11 2009, 01:24 AM

A lot of end-users always think that they are more genius than R&D engineer, and thus underestimate the complexity of microprocessor and electronics.

In the end they end up f*cking up their products and in return blame manufacturer for inconsistent build quality, reliability issue, overpriced after-warranty service, blablabla.

Doesn't only apply to Mac users, just anything else.
Personally I do know some guys who always encounter with freeze windows, virus-affected PC, crashed HDD, much more often than other people.

And what not. May the Mac always be with you.