This is the second time I've stayed at Auberge St-Antoine, the first about 5 years go. This time, I stayed 5 nights in a "Comfort" room.
On the positive side, the front desk staff and bellhops are very friendly, and the cleaning staff efficient, attentive, and effective (ie, the room was very clean and well-attended throughout my entire stay). The hotel itself is quite pretty, located in the old city of Quebec (yes, this means you'll be hiking it up the mountain if you want to head to the more commercial Haute Ville), has a few fireplaces in the public areas to lounge around in and read, and has really beautiful bathrooms in the rooms. It's also within a stone's throw of a few great restaurants (Il Matto not being one of those, for the record).
On the negative side, the room was cold (it wasn't terribly cold outside) despite turning up the heat, the sheets are VERY noisy - any sort of movement in the bed during the quiet hours was amplified, the bed far too soft, the pillows too high, the cafe staff seemingly oblivious to the idea of service, and, perhaps this is a one-off, but on my final night there, I was woken at 5:42 am by someone evidently dropping bowling balls in the suite above for about 10 minutes, followed a few hours later by earnest sawing and hammering. Who knows... your stay might feature a brand-new bowling alley!
Bottom line: I loved this place the first time I stayed. This time, I was disappointed by what I got for the price I paid (discounted as it was).