Had this recently. A lovely wine. It was better the night after opening, indicating a long life ahead. It also indicates that it needs a full whack of airing to show its best. So, to answer your question: decant!
The bottles in our cellar are just starting to throw a tiny bit of sediment, and I'm talking minute amounts, but I would decant not to get rid of the sediment (in fact, I recommend keeping it in this particular wine unless for some unknowing reason it's spitting out much more than I am seeing) just to bring it's life out. It's definitely on drink and will benefit from a decant for at least an hour.