very refined with its own character
I stayed here late September for a convention.
The location is excellent in my view, just a couple of minute's stroll along E Chestnut to Water Tower Place and Magnificient Mile/ John Hancock Tower. The quirky look of the building helps if you lose your bearings.
Check in was smooth and efficient.
My room on 9th floor was roomy, the bathroom spotless and the complimentary shampo etc was replaced quicker than could use it! 
The bed was comfortable.
A Big Plus here was the free wi-fi. I have a" thing" about higher range hotels charging for this, and I was very pleased that Sofitel delivered. (Are you listening Fairmont and Intercontinental?). 
As mentioned I was at a conference, so most of my dining was either off site or in the special delegate rooms. All good, but as a result I did not get to use the restauarnt facilities.
The bar was like most hotel bars, gets noisy and probably not cheap, but the staff were friendly efficient and used to coping with the numbers.
Would I recommend it?
Yes. The price was a bit higher than the Fairmont I stayed at a few weeks previously, even with the delegate discount, but this is a classy hotel, and the location combined with the excellent staff -everyone was willing and able to help with any requests- would make this an easy choice.
Dislikes? None really, but I was surprised that there was no beverage maker in the room- after 2 hours stuck in passport control and static traffic into town I was dreaming of a "cuppa". The only time I have found this before was in New York. The free wi-fi makes up for this. 
Particular likes: Due to the timing of my flight home I asked to hold on to my room until1 o clock. this was done no problem.