Matt's comparably equipped Dell trounced his PowerBook in a real world performance test:

• PowerBook: 58.3 seconds
• Latitude: 17.3 seconds

I've found that 1 GB of RAM isn't nearly enough for a PowerBook. I had to replace one of the RAM chips in my 1 Ghz personal PowerBook. I went ahead and upgraded to 1.5 GB while I was at it. Now Firefox feels 10 times snappier than on my 1.5 Ghz work PowerBook which still has 1 GB of RAM. I think I may spring for the maximum 2 GB in both.