Reducing the memory size to bring down the cost of the card seems to be a good move. Throughout all benchmarks the card still stay well withing acceptable FPS ranges. However, if you plan on using this card at resolutions higher than 1600x1200 you are better off getting a 512 MB card since then the memory limit will show up because of the increased video memory consumption.
I would have loved it if ATI used their new cooler which is used on the X1950, because it is so much quieter. Even with the stock cooler some nice overclocking is possible, especially on the GPU bringing it on X1900 XTX levels or even beyond it. The memory does not overclock so much because a lower speed grade of memory is used.
With a price tag of $300 this card will sure attract many users to choose the X1900 XT 256 MB instead of the X1900 GT which is only about $30 less expensive.