I scored a room at the Columbia Club via the housing system with around 6 weeks or so to go.  Prior to arriving I looked on their website and saw they were  a "members only" hotel with "strict business attire dress code".  I inquired here and other places and people informed me that they waived the membership and dress code for Gen Con but treated gamers badly and with disdain.

However I did not experience that at all.  The staff was friendly and polite and I never had one issue with them.  The bed was clean and comfortable,  the room was cleaned well each day and the room was quiet.  The bathroom was adequate, the hot water was hot though it took a while for the water to heat up.  The hotel did seem a little "musty" though.  The hotel is old and the room was not best room I've been in buy far but it was adequate and overall I would return there for Gen Con if I had too.

My experiences may be tempered by the fact that I treat a hotel room as only a place to sleep and shower, the only extended time I stay in the room is while I am asleep so I am rarely in the room.  I leave around 7am each morning and do not return until mindnight to 1am.  I sleep, get up and shower and leave.  So my expectations may be lower than others. 

I also stayed at the Columbia Club.

The staff were all very courteous, friendly, and helpful. The lobby is beautiful and spacious.

However, I had a different in-room experience. I may have higher standards of cleanliness, but they are not beyond reasonable. The bedroom part of the room was on the lower end of the acceptable standard, as there was a dampness to the carpet that was unappealing. I dealt with this by wearing shoes the entirety of the time I was in the room.

The bathroom, however, was not up to par.

The sink grout was lined with a brown slimy mold or mildew. What made this more visible was that the sink backsplash was a MIRROR. So I could see even worse levels of moldiness in the area behind the sink.

Every time I showered, the water would run orangey-brown for 10 seconds before it turned more clear.

There was no fan in the bathroom. This isn't a huge issue, but when the rooms already feel damp, it takes longer for the warmth and moistness to dissipate after showering.

Housekeeping was incredibly stingy with the amenities. My room originally came with 1 regular coffee, 1 decaf coffee, and 1 tea. Upon replenishment, I received 3 teas and no coffees. After I called down to the desk to request some coffee, they sent up ONE COFFEE POD.

I mean, come on now. Do I really have to request a number? In most hotels, if you ask for something (shampoo, coffee, extra towel, tissue, toilet paper) they send up much more than a single, simply so that you won't bother them again.

Like daveculp, I only used the room for showering and sleeping. So it wasn't horrible. But it wasn't great. If I had another choice, I'd take it. If it was my only choice, it would be acceptable (but not overwhelmingly enjoyable).
 

I am glad I didn't have those problems!  The hotel did have an overall damp and musty feel to it but our carpet was not wet and our bathroom was not bad.  

I am in agreement though, it would not be my first or even 10th choice.  I would stay again if it came down to the Columbia Club vs. not staying downtown.