Hi MIlos,
I have been using the combination of AX + P85/1.4 + Mutar I for a year. I cannot compare the quality of 85/1.4+Mutar with 135/2.8 because I have never used 135/2.8. I can only tell you my experience that they provide me the convenience though the weight is definitely heavier. The feeling of holding it like holding a 180/2.8. Because of my AX's extension function + the 2x, it also provides a significant macro work. The quality are good. Normally, there has no difference under the print of 8x10. Maybe the quality of P85/1.4 is so good. You can review the Forum of P85.
P8.5x2=170. My personal idea is that you have to ask yourself which range suit your style. Of course, 2 lenses are better than one lens. If you feel Okay. Keep the the 135mm/2.8 for awhile. As you are okay to use P85 + 2X, sell out the 135, and vise versa. If you are satisfied by both, keep them all.
Merry Christmas,
Francis.
