I lived on Central Square from 2006-2007, in the units right over Mirandas Veranda. I have to say that of the 6 places I've lived in Cheshire County, it was my favorite.
On the Plus side: It's a walk to anywhere. I could spend all night bar-hopping and come home and crawl into bed, no problem. I met a lot of people, and made many friends. People tend to hang out of their 2nd and 3rd floor windows on Main Street at night and its kind of fun. During Pumpkin Fest, my apartmnet became Party Central for people needing a bathroom, to rest, or to get a drink or some refreshments without paying three arms and a leg.
On the downside: Many Pet restrictions. Parking can be a pain, but you learn the 'routine.' If you drive 'away' to work in the morning, its not a big deal: you can pork overnight in the big lots behind Main Street for free. The only pain was Saturday during the day, but once Citizen Bank closes at noon (or 1 pm, I forget), their lot becomes free parking for the rest of the day.
Sirens never bothered me. What DID bother me was the damned street cleaners that would start as early as 3:30 am under my bedroom window - they were more obnoxious than any siren.