For the last few years I've been using the coach for trips to Western Europe (France, Belgium and Holland). Mainly it's for financial reasons - £30 return last minute in high season is doable - but I've warmed to it tbh. Amsterdam is about as far as I'd go by coach - but it's not too bad.
Best is to do it during the day, if you work remotely it's just like spending the day in an office with a nice changing view - I think all the busses that ply the route will give you wifi and a plug socket and the whole journey on modern busses on smooth motorways is really quite painless (except for the first hour and a half crawling through South London
)
Overnight is a bit of a chore and you're going to arrive feeling pretty shit so I avoid that now if at all possible and get an early morning bus.
It's a shame that a lot of the coaches go via Eurotunnel now as the boat, while taking a little longer breaks the journey really nicely and makes the whole journey a lot more pleasant.