I sat in those seats when we went to Boston and they were fine. Yes you are by the toilets but I never noticed it become a problem, perhaps because i was on a day flight and sleep wasn't an issue. The only problem i noticed was that because you are at the back of the PE cabin you are last to get served food etc and during my flight they ran out of both meat choices so it was vegetarian for me which i don't mind but for my partner it was an issue especially when they found him another meal but it was stone cold!
Whereabouts are you flying to?