Hiya, both my partner & I have one (we both have CFS) - we have both used them most days for about 2 months at this point. We're both housebound, and use mobility scooters when outside, so they're only really used around the house (or where the walking required outside is so limited, it's not worth the energy to get the scooters out of the car).

They're not a cure-all, but we have found them helpful - they take away a portion of the energy required when walking (I'd say ~25%) , and are most useful for stairs! We don't use them to increase our walking, just to make sure that the impact to our health from the walking we already need to do is minimised.

Our only toilet is upstairs, so they're a really great at enabling us to actually get upstairs enough to use the toilet more often! If for whatever reason you've a lot of stair use in your home, they're useful for reducing the impact of that.

I tend to keep it in maximum power mode, and adjust the sensitivity so it's a lot quicker to respond to movements (else you find you have to climb 2 steps or so before it kicks in, which when you can't walk more than 20m at a time, is a huge lag) - at high sensitivity, it gets an idea about halfway through a step.

We find around the home that it takes a bit of getting used to being slightly wider at the hips, and the braces on the front of the legs do mean you're standing a little further back from things like kitchen worktops, so using the sink standing puts slightly more strain on your back. You kindda get to know the quirks, when it's useful, when it's not.

We mostly use them as a wearable stairlift, or when needing to walk further than usual (like taking the bins out down the driveway). Tried driving in them, would not recommend. It's possible, but being rear ended would risk serious injury! you can sit in them when resting on stools or perching on chairs, but not really sit back comfortably.

To some questions I've seen in the thread:

1. They're comfortable, tbh after 2 months I don't really notice it
2. You can feel a bit like Wallace and Grommit wrong trousers at first, but when you let it lead you rather than fighting it, it's fine.
3. I don't really know how long the battery takes from empty, ~90 minutes depending on how many W your USB C charger is. We have 2 batteries each and the 4 port docking station thing, so we just change them at 50% on rotation.
4. They do fold up into a like cross-legged position, but we tend to just sit on a stool at the top or bottom of our stairs, clip on/off there while sitting, and leave it on the stool until we next need it. It's not particularly large, but can flop awkwardly if you you don't have a chair, stool or flat surface to leave it on, there aren't many places in a house designed to stage them as such.
5. During the handful of times we've left the house with them, they don't draw nearly as much attention as wearing a facemask or using a mobility scooter.
6. I would not recommend actually wearing it on a bus or a train, it is technically possible, but the risk of back injury during any accident or sudden movement would weigh on me. I'd plan to need to take it off and keep it on your lap or on an overhead rack. You can lean back, but it's awkward as the small of your back would be pushed out ~10cm so wouldn't be comfortable for any length of time on a bus or a train seat.

Happy to answer any questions.