I own one, and have tried it for both those uses, but with mediocre results compared to other techniques.
For crème brûlée, I get more even caramelization by placing the individual custards under a broiler. The only benefit I could appreciate from using the torch was that it was quicker, and I could monitor the caramelization more easily. (The broiler technique is the one recommended in this book for the perfect crème brûlée.)
For peppers, the torch dries out and blackens the skin without really cooking the interior. Again I have had better results in a broiler/hot oven, or on a grill.
The torch is most definitely fun, but so far I haven't found it to be necessary; I'll be interested, however, if someone else has found the perfect use(s) for a culinary torch.