I've visited this lounge many times. Because I travel for work frequently, I'm here about once a…read moremonth and have been for the past year. A quick note: this review applies only to the Aspire Lounge in Terminal 4. I have not visited the Terminal 2 location at Ontario International Airport.
Having visited a wide range of airline lounges, I have plenty of points of comparison. Overall, I'd rate this lounge a solid 3 out of 5. It's not great, but it's not terrible either -- kind of like the airport itself.
The staff do a good job keeping the lounge reasonably clean. I've never seen food scattered on the floor or overflowing trash cans. Contrary to some other reviews, I've also never had any issues with the staff. They've always seemed friendly and helpful. Another plus is that the lounge has never been overly crowded during my visits, so finding a seat hasn't been a problem. It's also fairly spacious, especially for a smaller airport. Some other Aspire lounges I've visited are tiny, consistently packed, and so cramped that moving around with luggage can be difficult.
But it does have some issues.
First, the coffee situation is surprisingly bad. This may not matter much for some, but having a good cup of coffee is one of the things I look forward to in a lounge. Ontario Airport doesn't have a lot of other options here either, as many of the other places that serve coffee close late afternoon and the vending machines are hit or miss (I've definitely lost some money in these). A while back, they replaced the cappuccino and specialty coffee machine, which frequently malfunctioned, with a newer machine that uses coffee packets to make different drinks. Unfortunately, the new machine rarely works either. I would say that in my last six visits, it worked once. Even then, the only available options were flavored coffee and decaf. Most of the time, there's simply a Post-it note on the machine stating that it's out of service.
As for the drip coffee, it's not much better. When it's available, it often appears to have been sitting out for a long time.
Second, the lounge hours are puzzling. Some days it closes as early as 6:00 p.m., which seems far too early given the number of flights departing later in the evening. About an hour before closing, staff block off half the lounge and begin making frequent closing announcements. On other days, however, the lounge remains open until 11:00 p.m. If you're coming here for the first time and have an early evening flight, definitely check ahead to see if its open.
Finally, the Wi-Fi has been unreliable. I've haven't successfully connected to the Aspire guest network the last few times I've been here. The login page appears, but there doesn't seem to be any way to complete the connection process. The airport's Wi-Fi network, flyONT, has been similarly unreliable and often won't connect either, so that's not an option either. This is the only airport and lounge where I've consistently experienced these issues.
Overall, the lounge is okay if you need a quiet place to sit and relax before your flight. I hope they address the coffee and Wi-Fi issues, though.