The ice skating rink in Le 1000 is open year round - and that makes it unique in Montreal. The rink is on the small side, and surrounded by restaurants. Therefore, Mommy and Daddy can keep an eye on their skating offspring while enjoying a cup of coffee.
The rink is usually packed with small children. Sunday and Saturday before noon are tiny tots hours - no big people without responsible tot allowed!
During the evening hours teens abound - it seems to be a popular dating spot. It also seems popular among dating teens to just stand around on the ice and chat rather than skate, taking no head of the obstacle they are providing to people who actually want to skate. If you want to socialize this is a nice place, but if your ambitions are more sporty go somewhere else.
All that said, this is a very pricey skating option. Admission is $7 for adults, skate rental another $6.50, locker rental yet another $2.50. Renting helmets etc. of course also costs extra - you get the picture. In winter this is clearly not a good option: Safe your money and go to Parc Lafontaine or Parc Jean-Drapeau instead! Both of these rinks are larger than the Atrium, and free.