In the current version you don't see the benefit of advanced lasers technology until the later end of the tech tree. It essentially allows you to build gigantic lasers. The tech lags behind regular laser technology up until 30cm focal size, where advanced is identical to regular lasers. After that, you start getting more bang for your buck. For example, in my current game I just completed 50 cm Advanced Laser Focal size, which allows me to build 80cm lasers. With an advanced spinal mount, that's 120cm of laser fun! The last level of the advanced laser tech is 80cm laser focal size, which allows you to make a Standard Mount 210cm laser.