Thanx to everyone for your comments, good and not-so-good.. the point of my letter to the GM was intended to be constructive. The hotel is absolutely filthy. I was told by Naoual that Sofitel had bought the property 2 years ago with the sole intention of selling it to Marriott, so they invested nothing in the hotel. This is quite obvious. When I say that there is paint missing in the halls, I mean that there are large chunks of paint where someone or something, like a laundry cart, as scraped by and torn off a 3 foot long piece of grey paint. This is repeated throughout the hallways. The rooms are so distasteful that it's almost ridiculous. Think of the rattiest, filthiest hotel in NYC and chop the room size in half and you have the Paris Rive Gauche Hotel. I just think that Marriott.com needs to be a little more upfront with people about the hotel. Even the staff are apologetic and seem embarrassed about the state of the hotel. The new room was a suite, nicer, much nicer. But the bed bug bites were still there and when there is no power and it continually goes out from just plugging in an iron, it gets to be a little ridiculous.
The room rate was €185 which for Paris is about average. But the room certainly wasn't worth the price. In a year when the hotel is completely refurbished, I'll book at the Marriot on the Champs-Elysees and then pop over to this hotel to check it out. It does have an enticing location (14eme arr.) and Montparnasse is just 2 mins away for those that like to stroll along the avenue away from the more touristy parts.
As for the reason I waited to send an email was because I did ask for the GM on Monday morning before we checked out and was told he was on vacation. I spoke with Brice and verbally gave him my opinion, but advised him I was going to send an email. The GM's email address was available at the front desk.
The staff are great! Just the physical hotel sucks!

I wish I'd had room photos on the marriott.com site before I booked.