Here I go then, right from the hotel (and before leaving, so perhaps I will get beaten up and locked in the basement after this).
The good news first - I am still at the hotel killing time waiting for my train from Gare du Nord, and as I had a prepaid rate, my account has already been credited with points before I managed to return the keycard. Also, surprisingly, I got the 4x credit for "new openings" even if I am not sure the hotel was on the list, but anyway, the key points is that YES, the hotel is excluded from exclusions and, being apparently a directly Accor-operated property, it credits points at lightning speed.
Another good piece of news is that the hotel, like every other 25hours apparently, has MINIs for their guests - they are rented for free, you just need to sign up at the front desk. They do not promote this too actively (but they do not hide it either - you can find leaflets informing of this in the hotel), so I was able to secure the car for an entire day rather than the usual 4 hours. Not only was the rental free but I was also told it is not necessary to even fill up the car - the latter may have been due to a general mess at the front desk or a conscious policy. Either way, I am a happy camper and love the concierge who had the morning shifts and our happiness in mind constantly. I regret not taking the time to put down his name which now eludes me
The NENI restaurant deservedly enjoys rave reviews both for its interior design, sumptuous (especially by Parisian standards) buffet and affable staff (again, something Paris is not famous for). I wholeheartedly recommend everybody landing at Gare du Nord in the morning to have breakfast there even if not staying at the 25hours.
Oh, and I should mention that the location is beyond brilliant - not that it is a surprise in the age of Google Maps and Streetview. Both for business and general sightseeing having Gare du Nord train, RER and metro stations right at the doorstep is as convenient as it could be - especially if you arrive / depart on a flight to / from CDG or on a train between Paris and London, Brussels, Amsterdam or Lille.
So much for the good news though - I will try to reply with a review in a separate post with the less rave-inducing details of my experience...