Anyone who enjoyed previous Splinter Cells should probably avoid this. It's a very lush production, with good visuals and sound, but it has virtually nothing in common with the previous games in the series.
It's a fairly competent shooter, but not excellent - most of the game can be passed by exploiting bottlenecks in the linear levels, mowing the baddies down one by one from doorways. It's one of those games that gives you a lot of different gadgets but contains one dominant strategy, rendering many of the available tactics pointless. The sneaking element is minimal, so much so that the majority of the game involves fending off player-triggered ambushes. The single-player is short, and uneven.
The story, if it matters, is midjudged nonsense.
Don't bother with this if you are a fan of the series.