I find this an intriguing topic. There is so much theory spread over the internet about what is better! I am right now in the process of doing a very relevant comparison. I have taken a series of photos using my 3.5 Rollei, my Canon FTb and a range of lenses and my Olympus E300 DSLR (8Mp), also with a range of lenses. All on a heavy tripod, in good light, all with comparable focal lengths and apertures adjusted to give equivalent depth of field and chosen to give the cameras the best chance. I pick up the 35mm slide film tomorrow; the medium format film is still in the camera. The digitals have been in the computer for a week already. I am really looking forward to seeing what "the truth" really is.
Despite what nearly everyone says, my experience has been that, when I use digital and film at the same time, I catch a lot more detail with slide film than digital. It also holds together much better in the more exposed areas, losing out to digital in the shade areas - which actually gives a much more pleasing photo for what I do (this depends a lot on what film you use - Agfa RSX was my benchmark when I could get it). I am convinced that I would need 12-16 Mp and lenses to match my FD lenses to equal the overall quality with digital. (My tests may prove me wrong!) I also like shooting film, I like being patient, I like making each photo count instead of taking a whole swag of them and then being tied to a computer for hours. But I still use the digital all the time.
I just get so sick of scanning slides and then correcting the scans to try to make them close to the original slides. A more expensive scanner would help, but I doubt I will ever buy one. Just lazy! In most cases, certainly up to the 12x8 prints I normally make, digital is indistinguishable from film. Bigger than that, it's not so simple. I get stunning 24x16s from 35mm slides - the prices I have got support that.
If picture quality counts most, the Rollei will beat the 35mm simply because of the big film size and decent lens. So why do I almost never use it? I find the fixed focal length too limiting and the back-to-front viewfinder frustrates me. BUT - I have a friend who gels with it. I went away for nine days with her and she took ten photos in that time. Every one was amazing (black and white) and would have been hard to acheive with the cheaper digitals.
The point of all this? All the theory in the world gets in the way of making the right decision as much as it helps it. Travel with the camera that falls into your hands right and gives the pictures you like. They will all give you good results. If you have the Rollei mindset, take that and expect to take your time over your fewer, expensive photos, which will reward you with greater quality if you make big prints. You might be surprised, if you weigh all your cameras, to find the Rollei is no heavier and may be lighter if you are taking an extra lens with the other cameras. It's also quiet, inconspicous and can be used with ridiclously slow shutter speeds. If you don't have the Rollei mindset, you will almost certainly get more "keepers" with your digital than your film camera, but the keepers with your film camera could well be better!
I know this hasn't helped much. I've taken it as an opportunity to let off steam. What the heck, I've written it, may as well post it.
One last thing. When I travelled around Australia a few years ago, I ended up selling a light zoom lens and carried around heavy Canon 24-70/2.8 and Tokina 80-400 zooms instead. The weight is no penalty when you get the shots that count (you can see some on deeppics.com, under "landscapes, Australia"). Really and truly, you may never get there again and the best lens is the most important thing.
Sorry about the rave,