Parallels Desktop RAM Allocation: Less is More?

There's been some discussions on whether it is better to allocate less RAM to the Parallels installation rather than as much as you can. Some say that you should not exceed 512Mb and other 800MB. Of course, I currently have it allocated at 1148MB... See a screen capture of my Parallels Console here.

There are some people's input on MacWindows.com: "TIP: Optimizing Parallels Desktop performance: Less memory is more". An example there was:
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Parallels Desktop:

764 MB of RAM
Windows XP boot time = 36seconds
Windows XP shutdown = 20seconds
Launching IE to MSN.com = 7seconds

512 MB of RAM
Windows XP boot time = 23 seconds
Windows XP shutdown = 20 seconds
Launching IE to MSN.com = 5 seconds
=================

So I did the same test just to see for myself, and I did not see much difference.

Parallels 1GB RAM Allocated to Windows XP Home
Startup: 45 seconds
Shutdown: 25 seconds

Parallels 764MB RAM Allocated to Windows XP Home
Startup: 43 seconds
Shutdown: 24 seconds

The above differences could have easily been my own error. I guess any difference would depend on what kind of set up you have and how much physical RAM you have. I ran both tests above with OSX (primary OS) running Entourage, Word, Safari, Firefox, iTunes, and iChat all active. So I guess it was a good thing that I have 2GB of RAM.

In any case, I am keeping the setting at 764MB for now to see if it makes any difference to the Windows side.

Interestingly there is a poll on the Parallels forum from users to input their feedback on what is the Mac System RAM vs the Parallels allocation. For 2GB RAM like mine, 10% of all voters allocate 1GB or more to Parallels, 37% allocate between 768MB and 999MB, and 40% allocate between 512MB and 768MB. The balance % were those who had less than 2GB RAM. This was out of 30 voters. I guess I will add in my vote now...