L' Hotel, Relais Christine, Madison or D'Aubusson

msheiny - Four great options, for sure. Surprised no one has responded. I have stayed at D'Aubusson three times and loved it. Quiet location, close to the river, etc. But last year we tried Relais Saint Germain and liked it even better. I think it's the best location in Paris-- a few steps from a two- line Metro stop, taxi station across the street, great staff, included breakfast, huge rooms. Tried to book Relais again for May but they were full so we opted for the Madison, just a couple of blocks down Blvd St Germain. It's more expensive than the Relais or the D'Aubusson, but it's directly across from St Germain des Pres church, Deux Magots, and, again, just steps from two single-line Metro stops. But, similar to your experience here, when I asked for opinions on Trip Advisor I didn't get any.
But all the reviews and specs are very good, so we'll see. Anyway, even though you have four great choices here, I would urge you to check out Relais Saint Germain as well. You will find it less expensive than any of the others listed here, if that is a concern. Bottom line, I can personally recommend D'Aubusson, and I hope I can return in May and tell you the Madison is even better!
Enjoy your trip.

We loved Relais St Germain when we stayed there a few years ago. We now stay in apartments in the 6th, but the location for all your choices is great - with wonderful restaurants, shops and transportation options nearby. The rooms are extremely comfortable and the staff very helpful.