For me it's about want and need. if I need a shot - whether for a brochure, event or whatever, I'll use D* - (I'll leave the '*' in there because it's fun). D* is fast, convenient, cheap (per shot), reliable and the results are great. You know you've got the shots in the bag, but there is very little creative connection in there for me. When I started with Digital, I was excited about working with images on a computer for a few months, then I got bored. I use computers all day, why would I want to hobby to use them too? I got record shots, a record of the object or person or event, the creativity that was left was in capturing the right moment, and that became easier and easier because I could just keep on shooting until i got what I wanted.
Now if I want a shot, I'll use film because I have to fully engage myself in the process. I have to decide how the scene and light will interact with a particular film. I may have to work with Velvia and have long shutter times (five minutes is my longest) which means I have to think about support, timing etc etc. Each shot is a challenge, then each shot in the darkroom is a challenge which takes skill. When I see a final result that has worked, I know it's down to me developing (excuse the pun) as a photographer, it's more me and less the technology.
When someone sees me struggling with an RB67 trying to do 1:1 macro of a flower on a windy day (this takes both number 1 and 2 extension tubes, a 140mm macro lens, and a very strong tripod head), they very rightly ask "wouldn't it be easier with digital?" And of course the answer is yes, but I patiently explain that it's about the journey, not the destination. I guess it's the same reason that I could hop in my car and drive to the Yorkshire Dales. It would be fast, comfortable and reliable. Instead, I'll strap my tripod to my Royal Enfield Bullet and ride there, you end up at the same place, but only one way gives you the satisfaction.