This is what I've done several times and I like it. I'm usually so excited about vacation going to Europe that I can't sleep and lack of creature comforts doesn't bother me, but it's nice to mitigate the depression of ending a vacation by knowing you'll be flying home in style.

That said if it were for business or if I wanted to get acclimatized quickly business class is actually more important flying TO Europe since the time change that way and the night flights means that if you don't sleep on the plane you're well and truly screwed. Coming back from Europe it means just staying up an additional 4-5 hours when you're sleepy, as opposed to arriving at 8am exhausted.