While I did think it was good with some sweet action sequences, at the same time I thought "didn't I already see this movie twice before?" as it was way too similar in plot and to the first two. The British girl was sort of bland in it as well. I gave it ***1/2 out of 5.
For me X-men: First Class was the movie of the summer ****1/2. Lots of really great characters and action sequences (beast kicked ass) and an interesting plot format (following Xavier and Erik until they met up). Kind of sucks it didn't do well at the box office though.
Haven't seen Harry Potter yet.