My Samsung Note 4 had a motherboard problem after the Marshmallow 6.0.1 update. I brought in my phone on June 22, 2016 and Pat was kind enough to ship it to Samsung head office for repair. Mind you, my warranty ended on May 12, 2016 but it's not my fault that my phone broke - it was working perfectly until the update which caused my motherboard to fail.
Gave me an estimate return date of 3 weeks. Didn't hear back from them. I had to keep calling them to follow up. Although when I do call and he's busy, he calls me back. August came in& there was no update as of yet. Pat spoke to another level of management to Samsung to get my phone fixed.
CPR ended up giving back my phone and it's working 100%. I had to be patient - Samsung changed my motherboard and it doesn't lag, reboot, restart and crash anymore. As for improvement, they need to follow up with their customers, however, I am really happy and a satisfied the customer service b/c they went above and beyond to get my phone repaired.
Paid nothing - Samsung covered it. Initially, Samsung was charging me approximately $400+ to change the motherboard. Thanks Pat.