I know exactly what you mean. I was big on that final low note too. But I'm just having too much fun playing the four string. Thin neck, shorter scale, lighter weight, etc... It's just more enjoyable for me to play than the five string.
I decided that one note in a song on the B string was not a reason (IMHO) to play the fiver. Once I did that, I now have a lot of songs (maybe half the playlist) to play the NS-2 on.
Plus, my fiver has the DCs/USA18v combo, and my four string will have the P/J pups with the USA9v and I want both those tones in my quiver.
After all, I'll bust my hump to entertain the people who come out to see me/us play; but, at this point in my life, I'm there to please myself first.
***edit***
Although I have to say that while I'm waiting for the NS-2 to arrive, I'm playing strictly my NS-5XL. So you're right, the fiver can do it all.