Depends on the build really.
Pros:
Cons
Depending on your build I think they can be really good, if you're already using Smithing it's kinda redundant though. Personally on my Arcane Bladesman I found them really good, as I could spend Smithing perks elsewhere.
In the end it's really dependent on the other skills your build will use.
If you're using Bound weapons you pretty much have to take Mystic Binding otherwise there's no point. I found Bound Sword's cost fairly negligible past level 10 or so but the Bow and Axe still have a pretty big hit, the bow in particular. The bow is a favourite of some assassin types, once you get quiet casting.
I'd have to disagree there, I find them perfectly viable later on. You can spam power attacks, and put perks into areas other than smithing, and the Bound Bow has pretty much infinite Daedric arrows and a crazy fire rate with the fire rate perk.
Of course if you're using Smithing to improve armor it's pretty redundant.