Which room did you book and which upgrade did you receive?
1 King Premium Montreal View Corner, received 1 Bedroom Suite Montreal View (room types are a bit confusing but this is a one-category upgrade)

How are the rooms?
So old that they could have been described as dated ten years ago! The only thing that was remotely new were the TVs, but to be fair things were still clean, comfortable and (mostly) in good condition. Was a bit surprised to find in the bathroom that they didn't have the brand standard Byredo amenities, there was one Byredo soap but the other items were a variety of completely random brands.

How is the exec. lounge?
Had access as I booked a Club InterContinental rate. Serves breakfast, evening drinks/canapés and all-day non-alcoholic refreshments, no afternoon tea from the looks of it. Evening service is from 5.30-7.30pm, everything was self-serve and they had a respectable array of food including hot pasta and chicken then a variety of cold items. For drinks they had a range of beers, wines and spirits including a French sparkling wine (not champagne though). Staff came through the lounge regularly to tidy up and kept everything clean and well stocked, they were also very friendly and chatty with guests. Seemed to be very popular - there was a large group staying at the hotel either pre-cruise or for some nautical themed conference and clearly going for a fancy dinner later, so everyone in the lounge was very much "dressed to the nines". For breakfast it wasn't super clear whether you could have the club breakfast in the restaurant or the lounge so I just went with the lounge, which was a good option. A variety of hot and cold items were available as well as sparkling wine to make your own mimosa. I was eating far too much good food in Montréal so was quite happy to have a lighter breakfast in the lounge!

What was good and what was bad?
Lol, maybe we can start with the bad? Buckle in.

• Arrived at midday and was advised the room wasn't ready. Fair enough, check-in time is 3pm but the receptionist was so confused at the request to store my bags. First she suggested I take them downstairs to the bell desk then she ended up taking them herself.
• Returned at 3.10pm, spoke to a new receptionist who searched the system for a good 5 minutes but still couldn't find a room. She went to speak with a supervisor (Perhaps to seek a further upgrade to an available room?) then came back and said they'd prioritise cleaning the room and offered in a way which suggested it was a special courtesy that she would let me sit in the Club lounge while I waited. I pointed out I had booked a Club IC rate so I was only being offered something I had paid for anyway and should have had access to by this point, it took her a minute to review the reservation and see I was correct. Didn't end up getting access to the room until 3.40pm.
• If I had to describe the shower, I would say it woke up and chose violence. There was one water pressure level and it was insanely strong, to the point where it took a while to adjust the showerhead to a level where it didn't hurt to stand under it and I had to turn it off regularly to let the water drain (I don't even think it was a blocked drain, it was just that strong!). I considered saying something but given it was a one-night stay, couldn't be bothered.
• I had planned to use my welcome drink vouchers at the hotel's Sarah B Absinthe Bar after returning from dinner. It was supposed to be last drinks at 11.30pm but when I arrived back at the hotel just after 11pm they had already closed.
• The Club lounge is in an odd location, in the lobby with no real views to speak of and random passers-by peeking through the glass to look inside. Hopefully a refurbishment is not far away and will bring a new location for the lounge.
• Both receptionists were trying to spin the fact I had been upgraded - as a guaranteed benefit of the Ambassador program a one-category upgrade is not particularly impressive. Tell me about it yes, but don't try to make it sound like I'm getting something I'm not entitled to as a way of trying to cover for problems.
• The aforementioned dated rooms.

The Good

• Excellent location in the heart of Vieux-Montréal - really easy to get around and see the sights.
• Great panoramic views from my "Iconic Tourelle Suite".
• As a Diamond Ambassador amenity I was offered a choice of fruit, cheese, charcuterie or mixed platter along with still and sparkling water. I took the mixed platter with sparkling water and the platter along with a bottle of chilled San Pellegrino were delivered shortly after arriving in my room. Appreciated this as not many hotels I've visited have offered welcome gifts beyond the standard IHG welcome amenities.
• Sarah B Absinthe Bar has live jazz early on in the night on Friday nights, walked past and it sounded really good.
• To her credit, the second receptionist was extremely professional and trying her very best at service recovery, she was just hamstrung by the situation that management has created for all the frontline staff to manage, so merci to Maxence! To be honest I could say the same about most of the staff, it's not their fault they've been let down by a management team who have not invested in or properly managed their property. My recommendation as always is if you experience similar frustrations as I did don't be too harsh to the frontline staff, be kind and they will be on your side.

Value for $ or Priority Club Points? Would you return?
Paid CAD $488 for the one-night stay. Primarily chose the hotel to make use of the 4pm late check-out due to a late flight the next day and it served its purpose there just fine, however there were certainly lots of other small issues throughout the stay which on their own might be ok but added up to be very disappointing overall. Would only return if the hotel is comprehensively refurbished or I need to make use of the late check-out again. If you are looking for somewhere to say in Montréal I can recommend Le Square Phillips Hôtel & Suites where I stayed for the prior three nights, certainly priced and marketed as a more moderate hotel but to be honest I enjoyed my stay there more than my stay at the IC!