Don't know what your friends are talking about, although noisiness really varies from person to person and location to location and house to house.
Any of these toilets would be appropriate for a hall bathroom.
There's no giant pressure-assisted whoosh on these toilets, and no click-clack or other weird noise when flushing. It's just a good flush and a relatively-quick refill.
The double-cyclone might be a smidge quieter insofar as it has maybe a little shorter gurgle at the end of the flush. Shades of distinction, and, again, depends on what component of the cycle (flush, fill, shutoff) makes it "noisy" to your friends or what your wife is concerned about.
The good news about these toilets is that you won't be using a plunger. Plungers make an annoying squishy noise, and sometimes a bit of a mess.
EDIT: Here's a simple video of the Drake Flush: Drake Flush
Here's a video of the same 1.6gpf Drake flushing paper. The distorted noise you hear during refill is just a distortion of the sound of water dripping; it sounds weird when the camera mic is right next to the toilet. It doesn't sound like that in real life; it's just a hiss of rushing water with a little dripping sound. Slurp, gurgle, gurgle, gurgle, hisssssssssssssssssssssssss, tap. Drake G-Max Flushing Paper
Here's a video of the thing working with the lid off. It's the whole cycle, from flush to completed fill. Again, you can see that there are no unusual or loud noises, even with the cover off the tank in a very acoustically-live room with hard tile and a glass shower immediately to one side of the toilet. Full Drake Flush Cycle -- Tank View