I think my shortest start to finish image (including modelling, texturing, scene building) was about 3 weeks which means about 25-30 hours - that was my Ents pic. My image making times tend to be a bit longer as I often take breaks during making an image... 3 or 4 days of no bryce just to let things percolate through every so often (and to escape the monitor, play some sport...). I also tend to wander off and try something different at times during a long image making process (I often go and play around with some organic modelling projects of mine), so the main image project just sort of stops for a while, but when you're on personal projects, you can work at your own pace, so time isn't that much of an issue.

Dreams are just nightmares on prozac...
Digital WasteLanD