I attended both SA & SC this year, back-to-back. I had a great time at SA. As for SC, not so much.
My first (and biggest) complaint was in my section of seating. I sat in section 7, opposite judges side, great view from center. Unfortunately, I quickly discovered there was some type of 'VIP lounge' area on the upper level behind section 7, separated from the audience only by a thin black curtain. This VIP lounge was not accessible to regular ticket-holders. There always seemed to be a high volume of noise coming from this area, including the constant murmur of conversations, sharp bursts of loud laughter, and the constant clanking of dishes/silverware. It literally sounded like there was a full-service restaurant running back there. Most of this occurred in the middle of competition while skaters were on the ice. At a couple points, I heard the dropping of dishes on the floor and shattering of glass. I'm pretty sure the noise carried further than just my immediate area, because I saw several people sitting 5+ rows in front of me who turned around to check where the sounds of breaking glass and bursts of laughter were originating.
Food options were terrible. It's an arena and I wasn't expecting much. Most options were pre-packaged and barely edible. One of the few 'fresh' food items were the hot dogs, and they were absolutely terrible. Concessions were frequently overwhelmed, understaffed, and under-stocked. Equipment didn't always work. I had problems buying a can of beer w/ cash during the gala because the person running the stand 'couldn't log in' to their station. The arena was in the middle of nowhere, so leaving would require at least a car (as well as missing a portion of the event). Looked like hundreds of folks (especially Japanese) were being bused in every day and had nowhere to go.
Washrooms were poorly maintained and often gross. The lines (especially for ladies) were atrocious, and hadn't cleared even during the duration of an ice resurfacing.
The arena seating area itself was never cleaned over the course of the day. Trash and bottles accumulated all over the place beginning in the morning and were still there later that night.
Traffic was bad leaving on Friday night. Total gridlock in the area in and around the parking lot. Took me an hour to get out of it. Traffic was okay for the remaining nights.
I heard booing during the Free Dance session, but never at any other time over the weekend. At various times, I also heard the crying of an infant or the clicking of cameras. None of it seemed to be originating in my immediate section though. Quite honestly, I'd have preferred to sit closer to all the other sounds v.s. the noise of the party going on in the restricted lounge behind me all weekend.
I clocked a new personal record in Mississauga: I was in the arena on Saturday from 7 AM in the morning till midnight, without ever leaving!