Is there any negative regarding the Cu-Ni tubing (except that it does not look like steel)?
The Cu-Ni certainly flares and bends easily. The only negative aspect I can think of is the materials flexibility. In heavy brush, the lower tubing applications (as along the rear axle) may catch and tear more easily than the more rigid steel or stainless steel. I just installed some Cu-Ni on an old beater firewood hauler...I will monitor for product durability.