Tuner technology has not changed. If you are looking for a new tuner, there are very few produced anymore. I have a Magnum Dynalab which is the only company left that makes new high end and expensive tuners. As long as your tuners are working I doubt you will need to upgrade. This is a site that explains everything that you would want to know about tuners!
http://www.fmtunerinfo.com/
http://www.fmtunerinfo.com/