I have sat in all 4 rows and I can't say that I have noticed much difference in extra inches so to speak. Row 1 feels it has a little bit more space but I have never had my measuring tape with me to confirm. In terms of lighting/noise, I think you will only notice this if you sit on the aisle in Row 1. There is also a toilet on the right hand side right beside 1G/1H which means that people will be passing which could bother you. The toilet on the left side is more forward just at the cockpit door. Talking about the noise, this is usually kept to a minimum as the Cabin Crew like to settle down after about 2.5 hours into the crossing and you don't see much of them. My own favourite seat is 4K because people in my experience like seats in Row 1 and 2 which results in me having no one beside me in 4H on a lot of occasions. The only trouble with Row 4 is that sometimes the meal you want has already been ordered by people in front of you so you may not get what you would like. To remedy this, just mention it to the cabin crew when they first come round with drinks after take off and they will always hold one for you. All in all I think you will find the experience agreeable.