Pros
Nice coworkers
3% matching IRA
Cons
You will be working the day after thanksgiving, Christmas Eve, and New Years Eve and many other federal holidays like MLK jr day and Juneteenth.
I was lied to about the on-call schedule. I was told that on-call would be once a quarter, and it would be 7am through 10pm Monday through Sunday. However, coworkers have told me it's more like every 6-8 weeks, and it's 6am through 10pm. It's not a typical on-call where you're just checking for emergencies, the manager will push you to do work at 6 in the morning, including the weekend. You are not able to go out that week because you have to be ready to work at a 15 minute notice. You won't get paid for the work either, only an extra half day off if you choose.
You are also forced to bill as much time to the client as possible, because they make profit from it. Even if you're not actively doing work, you're encouraged to be sneaky about how you're billing it to the client. If you don't have enough billed hours they will start harping on you. Very ineffective for an MSP which makes sense given that every other month you'll get an email about someone who quit or got fired.