While the Garden is beginning to show it's age, these seats are just fine if you want a cheaper alternative to the lower levels.
The upper level corners are easily going to be the cheapest tickets in the arena though Celtics and Bruins tickets are not cheap in any sense of the word.

I enjoyed the seats though I do enjoy being closer to the action. We could see the floor just fine, it was just hard to make out who the players were. The jumbo screen in upper center has sharp presentation and allows you to keep up with what's going on rather easily. My only complaint would be the beer rule for those that don't have MA driver's licenses.