The following I posted as a comment on a walden effect blog about personalities. I thought is was worth repeating here.
As for some personality being a blessing and a curse; personalities are complex. I dislike A/B and other personality labels; they're too symplistic IMO. There is no black/white and A/B. It's more of a gray area. Contemporary psychology uses the big five personality traits model, where for each trait people lean to one or another end of the scale. If you read about these traits you'll probably recognize where you stand pretty easily. But I think that these traits are not constant over our lifetime. We live and learn. I for myself know that I'm not the same person I was ten, twenty years ago. So you shouldn't accept these traits as unchangeable.
It is however much wiser IMO to make use of your strengths than to keep trying to fix your weaknesses like some improvement programs suggest. The former is much more rewarding.