After 2-1/2 weeks in France which included several "budget" hotels, we decided to pay more for a luxurious final stay in Paris. While the Sevres Saint Germain was certainly adequate, it did not justify the extra cost.
On the plus side, the staff was helpful and the bath towels were huge! The shower was also enclosed, so water didn't splash all over the bathroom floor like at the places that only had a small "shield" mounted next to the showerhead. On the downside, the bed wasn't very comfortable--we both woke up with sore backs, which hadn't happened at any other hotel--and the walls are not well-insulated against sound. We were both woken at odd hours by travelers moving around (packing, unpacking, using the wc) in their own rooms. There is a lift, though (as with several hotels in France) it's only big enough for one person with luggage at a time. As mentioned above, the staff was helpful, loaning us a plug adaptor so we could re-charge our camera batteries and giving us a cup of ice when we requested some.
What you're really paying for, I believe, is location. This hotel is in a quiet neighborhood (except for the early-morning garbage collectors) and it's safe--we were able to walk back from the Metro station after midnight with no worries.
Finally, we did NOT eat breakfast here due to the insulting overpriced cost. Luckily we had already stayed in ten other hotels on this extended trip, so we KNEW that every other place charged between 9 and 10 Euros for breakfast. For the EXACT same selection (we checked the hotel menu), Sevres Saint Germain wanted 15 Euros each! We got croissants at the patisserie next door and put those 30 Euros towards a nice dinner instead.:-)