Scent: Slight
Petal Count: ~30 is a guess, as this was my first time counting petals.
Blooms: single bloom per stem, not clustered. Repeat bloomer. The shape of the flower is kind of pointy/swoopy... I sometimes think they look like wings. Large.
Bloom Color: Creamy white center with pale pink outer petals and edges. As it ages, the pink fades. It was more white during its first April bloom, and is slightly more pink in its second July bloom. Reverse seems the same as the top.
Foliage: Dark with large leaves that seem somewhat resistant to getting eaten, though not entirely. 5-7 leaves per stem depending on how old the stem is. I'd say the leaves are more matte than glossy.
Thorns: Lots of them. Thick, poky... only place they take a while to show up is on the flower stem.
Overall plant: It's tall and sturdy. It's currently near my height (5'6").
Soil: The soil around it isn't the best. It's hard and likely full of clay.
Sunlight: It gets full sun to part shade through the day.
Zone: I'd say I live in Zone 9-10, more on the 10 side.
Age: I haven't a clue. But I'd guess 5+ years based on the surrounding area, how hard the ground is to do anything with, and knowing the previous owners didn't do much except maintenance.
Additional: Sometime before I moved in, suckers came out and stayed out. There's a small wild red rose that shares the bush now. At a guess, it's somewhat stunting the growth of the cultivated one, since during the biggest flush of flowers in April there were a ton of small red ones just after the white ones finished. I don't think there have been more than 8 white blooms open at one time. But it does seem to be mostly holding its own.

Bloom #1 from 18 July 2008. Doesn't seem as pointy as usual and the pink is really deep.

Bloom #2 from 18 July 2008.

Blooms from 2 July 2008.

Bloom from 15 April 2008.

Aged bloom from 14 April 2008.

Bud from 16 July 2008.

Reverse from 18 July 2008.

Example of thorns, taken on 18 July 2008.

Full view, taken on 18 July 2008.