I have Object Desktop, which I run on a 3 year old IBM Thinkpad 600E, PII 366 with 128Mb RAM and Windows 2000.
WindowBlinds runs fine (although sometimes I get some strange artefacts like buttons losing their skin or random scroll bars appearing in the middle of windows!) as does ObjectBar, DesktopX and CursorXP. WindowFX is a total non-starter however, it really does slow things down and some effects won't work at all.
I think the key factor is not the processor or memory, but the graphics system (as with desktop machines, I guess). If you are thinking of buying a new laptop, or one made in the last year or so, you should be fine. Around that time, the manufacturers realised that people wanted to do 'normal' things like play games or watch DVD movies on their laptops, and started to put decent hardware acceleration into the graphics chips.
I bought OD to amuse myself while I am working away from home - hope you have as much fun as I have had

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