I think Laura Linney is an exceptional actress. I rented this movie based on her ability to carry a plot. The plot synopsis sounded like it had a bit of the supernatural, which I tend not to like, but I thought the acting may be able to overcome a marginal plot line.
As it turns out, I think the synopsis overstates the reincarnation angle. It's really about relationships; the realism of adult relationships and the idealism of adolescent relationships. It's also about how some people struggle to overcome the emotional immaturity of their teens. It's about rivalry; love found and love stolen, but it does so in a way that isn't cliché.
The characters have a nice arc to them. Laura Linney's acting was up to my very high expectations. Gabriel Byrne turns in a solid supporting performance. Topher Grace also does an OK job, but seeing him work next to actors of greater stature, the contrast was evident.
If you enjoy character-driven plots, with good acting and few clichés, then you will enjoy this movie as much as I did.