Performance Chips

I have recently purchased a 1999 Sonata with 160k miles on it, it has been kept in great shape with a replaced transmission at 100k miles. I have been looking into performance and economy chips, and I am wondering if it is worth it (not because of speed, but fuel economy and smoothness). If anyone has put one in and has any recommendations and/or advice for me it would be much appreciated!

Thanks,
Tommy