Strictfp gives you more repeatability but less performance and generally less accuracy.
strictfp can actually improve performance, depending on the CPU architecture and Java implementation. Think about it. If variables are stored in IEEE format and a different format is used for intermediate calculations, then there is converting going on and that takes time.
The difference in accuracy is not significant in any practical sense. The IEEE formats were designed so as to divy the bits up between the exponent and the significand in a way that works for nearly every application.
Its worth it for a Java developer to be aware of strictfp. We have all been sold on the slogan, "Write Once, Run Anywhere", but it really should be "Write Once, Run Anywhere...But Get Slightly Different Floating Point Results Unless You Use strictfp".
If you can't learn to do it well, learn to enjoy doing it badly.