Review after 4 years of use and before I give my opinion, here are a few details that aren't obvious from the marketing material:

The top edge of the ceramic bowl is 43.5 cm above the floor (with the threaded rods at a height of 33 cm).
The opening of the bowl is 24.5 cm wide and 33 cm long.
The opening of the seat is 20 cm wide and 30 cm long.
When the lid is open, it doesn't rest against the wall behind. It stands upright, slightly away from the wall. The open lid is about 53 cm above the bowl, so roughly 96.5 cm above the floor. Depending on your cistern, the flush buttons may end up behind the lid, so I'd recommend measuring first!
There are two different remote controls for this toilet. I only found out that the small one is the new model because I asked a question here on tooaleta and Grohe support answered it. Unfortunately, the product number for the complete set hasn't changed, so you don't know beforehand which remote you'll get. Almost all the marketing material shows the old model. The differences are the size, the orientation (the old one is horizontal and the new one is vertical), and physical buttons vs touch buttons. The new remote has a display and settings buttons on the back. With the new remote, two of the toilet's functions can't be used: soft wash and massage. On the other hand, it has three buttons for operating the seat and lid. With the old one, you can only "raise everything" or "lower seat".
Both the ceramic and the electronics unit are "Made in China".
Grohe advertises it as "Engineered in Germany". That's probably a bit of a stretch. They may have had a say in the shape of the bowl and in adapting the connections to German standards, but the product was developed by the Japanese parent company, Lixil. In Japan there are several models with identical technology under the INAX brand. In the US I found two identical models, with a few country-specific tweaks: the DXV AT200 LS Spalet and the American Standard Advanced Clean.

Now for my verdict:

+ The flush works really well.

+ The washlet function also works well, once you've worked out what suits you best after a while (sitting position, settings).

+ All the materials feel very high quality.

+ The odour extraction and that ion thing really do seem to make a difference. At least, I like to think so.

– Unfortunately, my bowl has a small flaw in the glaze: a black dot in a particularly annoying spot (see photo). Obviously you don't send a product like this back for that (well, I wouldn't, anyway), and by now I don't even notice it :) but it's still annoying ...

– The business with the remote control models: I find it really annoying that you don't know beforehand what you'll get. It's also just plain lazy of Grohe's marketing department. I wrote to customer service asking whether they might swap my remote for the other model. I got a one-line reply asking for my phone number so they could ring me. I thought that was a bit odd, but I gave them my number anyway. The call never came. What I did get was an email with a questionnaire: "How satisfied were you with our service?" In the end I bought the old remote second-hand myself :(

I find the old model much better. The display is really helpful, and I'd quite like to be able to use all of my toilet's functions, if that's not too much to ask. Also, I think everyone's had trouble with touch buttons at some point. Even though they worked very well here, physical buttons are simply more reliable. (When it comes to cleaning, the touch buttons do have a slight advantage, of course.)

When I asked my question to Grohe pointed me to the app. It does work, but I don't want to take my phone into the loo. Also, it takes 20 seconds to connect every time (on a Samsung Galaxy S8).

One more thing: the old remote itself comes in two versions, which differ only in their firmware. The older version came with the older model of the toilet (model number 39354SH0), which didn't yet have the descaling or ion cluster function. That older remote works just as well with this new toilet. It just lacks the ion cluster and descaling settings, but those can be set via the app.

– While we're on the subject of the ion cluster, I've set the ion function to "Room", which means it switches on once a day for a longer period. However, whenever I close the lid, the toilet starts making the same noises it makes when the ion function is running. Grohe's answer was that this is normal: the noise is always there, but the function is only active when the blue light is on.

I find that rather bizarre. If my toilet is apparently doing something all the time, I'd quite like to know what! Besides, on mine the blue light does come on when the lid is closed! As a test, I switched the ion function off completely, and then the noises with the lid closed stopped as well. I don't really mind, as I always leave the lid open. Sadly, though, it shows that customer service haven't got a clue and that the toilet's software isn't properly finished.

– Speaking of the software, it isn't properly finished in several respects. The toilet must have two sensors for detecting people:

a proximity sensor for when someone approaches, which opens the lid if that function is switched on
a sensor that detects when someone is sitting on the toilet

If you set the night light to "automatic", it isn't on all the time, only when the toilet is in use. However, it doesn't use the proximity sensor for this. It uses the "someone's-sitting-on-me" sensor. So the light only comes on once you've already found the toilet and are sitting on it. I'm sure your privates appreciate the illumination ...

Another bug (although it's actually described this way in the manual): you can trigger an extra cleaning rinse of the nozzles from the remote. But this only works when someone is sitting on the toilet. Where's the logic in that? (The nozzles stay retracted during this function, so there's no risk of water spraying anywhere if nobody's sitting there.)

Things like this could be fixed with a firmware update, but I doubt Grohe has anything like that planned. That's the trouble with buying a tech gadget from a plumbing company ... ;)

– Spare parts are absolutely extortionate, both at RRP and at actual shop prices. The descaling kit is a few plastic parts and a few grams of citric acid. It has an RRP of around €140 and a street price of £80. The old remote is £470 (street price £250–£280). For that money you can get an entire bidet toilet from other brands ...

Bottom line: despite all the negatives, I'm not unhappy with the toilet. But if I had to buy one again, I'd look at the alternatives veeeeery closely!