What will be better OSX Snow Leopard or Windows7?

Both are being updated and both will be available around September. I am curious on your opinion.

The reason that I ask is that I have had very poor experiences with VISTA. (My wife’s Vista notebook had a lot of trouble with roaming in our wireless home network, for instance.) I therefore migrated to an apple notebook about a year ago. Now my wife wants / needs a new computer and we are tempted by the better prices for windows computers. Now that VISTA will become windows 7 it seems that it may be just as good as OSX. In that case, we may postpone until windows 7 is released. Alternatively, we might still rather buy an apple laptop and enjoy the free update when snow leopard comes around.