Enough? Yea. Vista WEI score is going to be in the mid-upper 4 range. Showyourscore.com has the best score as a 4.8.
scores in the 4 range will do all the Vista eyecandy.
But is that "good enough".
Sure.... Maybe...... But.......
For a few bucks more, you could get a 1950 from ATI or 7900 from nVidia. Any of the cards from those series are going to give you WEI scores approaching 5.9. And with the new cards hitting the market, the prices for the 1950 or 7900 should be dropping. Doubtful the 1650 would drop much in price as it has most likely already bottomed out in price.
Personally I would shot for scores above 5.5 as that level of equipment will be more than satisfactory for the next couple years. Some graphics and video editing applications are suggesting cards with 5.5 scores as their desired baseline score.
And depending upon your display size, it could be very desirable to upgrade to a faster card.
visit showyourscore.com. The site is primary for ego boosting, but the results do indicate a range of performance results that anybody can expect with their equipment.