Definitely better than Sheraton Charles
I just arrived yesterday. The Sheraton Charles Square is not as nice as this place. Actually, I wouldn't even use the term luxury when describing the Sheraton in Prague - there's no real doorman, the check-in is rushed and without platinum recognition, I did not get an upgrade - was told we are painting the room. The club lounge at sheraton had many beers in the fridge which were warm. There was no food out the two times I went (evening and then morning).
I checked out and got a room at Augustine which is spectacular. The entrance is really cool its an awesome courtyard and the whole hotel is a redone monastery with clearly very recently redone rooms - all marble bathrooms, bidet, sitting area and closets are all great ( They upgraded me to a suite without even asking). The area / location of Augustine is very close to charles bridge and the palace. No complaints. your results may differ.