Are we talking about the same thing. A main OS, means, to me, one where you are storing all new data and file. As an alternative, but in dail use for testing and getting familiar with -OK
I do not know what the "others" said, but Paul Thurrot certainly would never reccomend running a Beta OS as the main OS. If you have definite plans to hack the activation, which we cannot discuss here, or you intend to buy, and overwrite, with the real thing. Then you are on a reasonable path.
What Paul Thurrot actuall said was,
quote "That said, you're mileage may vary, so approach any install of this Beta with caution, and be sure to back up all of your important data ahead of time. I have not upgraded any Windows Vista PCs to the Beta yet,"