Hiroo's a really nice neighbourhood. The walk to the station takes you by some great coffee shops and bakeries (Sawamura is recommended, although a bit expensive), and Arisugawa-no-miya Memorial Park is beautiful. Towards Ebisu Station, there's a number of nice restaurants, including some great Korean hotpot. If you're in the mood to really stretch your legs, walking to Shibuya, Harajuku or Naka-Meguro is not out of the question, although you'll want some comfy shoes.
Weak point is probably the distance to the JR Yamanoto line (~15 minutes), plus the number of transfers necessary for a lot of popular locations if you take the metro—although the Hibiya line can get you to Ueno quite easily. When booking in Tokyo, it's usually a good idea to work out where you will be spending most of your time and how you will get there in order to figure out whether a given location will be convenient.