The dynamic range of digital is superior to slide film of any kind in my experience, and if you use a tripod you can considerably further enhance the dynamic range by taking two or three different exposures and then combining them in Photoshop, a trick that's hard to replicate using film because of registration errors.
There are economic reasons why purchasing a 22mp back might not make much sense to many, but you can get 95% of the perfomance at 25% of the cost, so all is not lost.
My workflow with digital is so much more economic and pleasant.
With film it would be: buy film (ouch!), take shot(s), take film in for development, wait a day or two (or pay a premium for fast turnaound), pay throught the nose for reliable development (ouch!), carefully mount trannie on drum with oil, overlay, tape etc, scan. spot scan in photoshop, realise I flunked the exposure slightly (it happens), finally get to work on the image several days after I took the shot.
Witb digital its take the shot, check exposure and re-shoot if required, transfer to PC (cold beer) and decode raw files, and begin work - ofter all on the same day. No cost, no hassle, more focus on the image not the process.