I really like the Transfirmer. The workouts that come with it are fun and really hit the glute area. Lunges on the incline, incline stepping, leg preses and step-ups onto the 14" portion are all included, and effective for that are in particular (I used the workouts at the beginning of my 'rebuild the butt' rotation...which I need to get back to!
I don't think they would be too noisy. There are some plyo moves in the floor cardio, but they are optional.
The Transfirmer is also a nice piece of equipment: the Firm finally got it right! You could also use it for other workouts and take lunges to the incline (seems gentler on the knees, but tougher on the butt, a winning combo, if you ask me!)