I must say that I prefer the series 1-3 dungeon, before they went on safari. I prefer the graphics; lots of nice colours. I also like the fact that each room was different to the last one - you never knew what was coming next. Looking at it psychologically, I'd imagine the inside dungeon would be better at creating suspense because the Dungeoneer is trapped. In a wood, there is somewhere to run to. It is, after all, a far friendlier environment (in terms of human instinct).
Also, the action and pace tends to get a bit diluted when there are Eye Shield sequences every few minutes.
I'm not sure what a mixture of outdoors and indoors would be like. Mind you, if the outdoor scenery looks as nice as the series 1-3 style dungeon (not to mention the indoor scenery!) and if the pace is maintained (which I'm sure would be the case now that the need for guiding has been dispensed with) I think it could work.
Then again, I've never really been a fan of the more Tolkein/Pratchett-esque side of the show. I've always loved the sci-fi flavour that the show has always seemed to have ("manifestation," the Life Force clock and the clever play-on-words in spellcasting, to name a few examples) but particularly so in the early series. I quite liked the Technomancy theme in later series but I think that was mentioned and discussed too explicitly. In the early series the underlying sci-fi theme was only ever implied, nothing more. I think that's flasher and, ultimately, more menacing.
