Honestly, I roll in the open because I find that it generates better experiences. I find that, for me at least, having the results be generated without my input makes the end result more interesting.
OTOH, on the occasions where I do "fudge", I tend to do so by having the bad guys make mistakes or perhaps choose less than tactically smart options. Maybe that one guy gets stuck in the mud for a couple of rounds instead of just going around in the first place. That sort of thing.
To each his own.
The last time I played with a DM who rolled in the open a game that we were enjoying came to a crashing end and no one not even the DM had a good time and we all agreed that it would have been better if he had not been rolling in the open.