i'm currently using arc10 3u and wondering the difference between the arc and the mx80 (either 3u or 4u) is 3u mx80 too demanding?
3U MX 80 will have more smashing power as compared to the 4U, however 4U will be more faster than 3U. 3U MX80 is more agile than Arc 10 though. Several people would find that shaft stiffness of MX80 to be quite difficult to handle. MX80 shaft would be stiffer than Arc10.