So now I'm starting to be fairly impressed by Nik HDR Efex. Though I like the first version of Grid #11 processed in Photoshop CS5 HDR Pro, HDR Efex delivers visibly extra detail and color depth.
The monochrome conversion was processed in Nik Silver Efex Pro with a light green filter and aqua/sepia split tone applied in Lightroom.
Camera: Nikon D700
Lens: Nikkor AF-S 50mm f/1.4G
Exposure: ISO 200, three brackets around f/11 @ 1/200s, tripod, RAW
Lighting: Direct daylight
Location: Alley behind the Grand Center Artist Loft Studios GPSProcessing: Lightroom 3, Nik HDR Pro, Nik Silver Efex Pro