Hope you are enjoying your new Tak doublet. I have been observing with your old 115S and it is excellent. The reason for the unevenness in illumination was probably because the last baffle was loose partially blocking the light cone coming into the telescope and the lense had some suburban grime on it. The focuser also needed straightening. I had this fixed easily here in Tucson and the images are now perfect! The Vixen also weighs less than the Celestron 120 Esprit, about the same as an 8inch SCT.<br>