The bonding that I had done only lasted about 2 years. I had it done for free by a very nice dentist. (an older gentleman in his 80s)....I drank through a straw between my lips and 2 front teeth growing up, and wanted them filled in so to prevent cavities. I like it....but it doesn't last very long.
I had bonding done on one tooth that I chipped when I fell. It was 4 years ago and it still looks great. I don't have anything negative to say about it. It sure beat having a crown and/or root canal. However, for doing entire teeth, I'm guessing you'll need some sort of local anesthesia, which I did not.
The only other thing I would add is that I think if you just get 4 teeth done it might look a bit "unfinished" especially if the rest of your teeth look significantly different naturally.
I've had a bonded tooth on the side of a veneer that went wrong, ie. chipped (about 20 years ago). It's still going strong although it's slightly more yellow and I can see a brownish line developing where it began. More cosmetic dental work beckons, and it ain't going to be cheap...