I had the Advents many moons ago and I thought they were a great speaker! I have had many since(40 years). I still prefer a simple two way sealed design like the Advents. You should listen to a good monitor like the Harbeth P3ESR(now own) or the Spendor 3/5r2. You will be amazed what these speakers with their 5 inch woofers can do!
Upgrading from Large Advents?
Though I love how they sound overall, I was wondering what suggestions you might have to give me more of what they do well: coherence, flat frequency response (I use BSC with 3dB midrange reduction), and a certain comfortable musicality that I haven't experienced with horns or planars. Are there modern, better speakers with a similar character? I've upgraded the XO components in addition to the BSC insertion.