Well I have recently purchased some JBL GTO's 625 and decided to give a little review on them.
INSTRUCTIONS: The instructions that came with these speakers were quite poor. It consisted of a two page booklet which did not even mention their special mounting ring technology. This left you to guessing how to mount the speaker. It did contain information about the full line of GTO speakers and it did touch a little bit on the installation.
TWEETER: I was impressed with their tweeter technology--especially the swivelling tweeter that they incorporated in it. It can turn 360 degrees and tilt only 15 degrees. Although 15 degrees isn't very much, I realised that if they would have allowed to tilt any more it might have conflicted with the woofer's cone. The tweeter itself is not harsh on the ear and has a nice crisp sound to it.
DRIVER: It has very well defined mids and a very nice warm sound. Although I am only running these off the HU right now, the mid base was very present and that impressed me. It has a kevlar cone that seemed quite strong, but the surround seemed very easy to puncture.
OVERALL: I think this is a very nice, well balanced set of coaxials. They did a very good job on the speaker itself but severely neglected the manual. This cost $120 in the Bahamas (about $60 in the U.S.). For that price I think they are well worth it and should not be overlooked.