Pros
Every implementation is different. Last quarter I had a banking client and an automotive manufacturer running in parallel which sounds nuts but worked because the senior on my team divided client meetings between us cleanly. You learn how to read a client's signals fast — when they say 'let's see the report next week' it can mean five different things. The team will mentor if you ask, which not every consulting-flavoured firm does.
Cons
When two go-lives overlap, the workload is real. There were six weeks last year I worked through alternate Saturdays. We're told it's getting better and structurally I can see planning improving, but if you're sensitive to spikes this is something to weigh. Good fit if you don't mind seasonal intensity for the variety.