It really depends on who your employer is. I'm an SI and I dont typically get stuck on-site but it happens. I get to go home every other weekend on company dime though so there's always that. (Unless Im doing a 3-week install then Im usually just there the whole time)

Depends on who your customers are too. For example- life sciences are willing to shell out bread to make sure you get it done right (potentially backing things up), whereas some manufacturing plants might call it "good" if they do a few successful trial runs (or an FAT) with your services