Each tractor owner will have a different experience with component service but consensus is 3,000 engine hours tractor DPF service life.
The average residential compact tractor operates sixty engine hours per year, according to industry surveys.
3,000 hours DPF Life / 60 hours = 50 years of residential use prior to DPF replacement.
Diesel Particulate Filter supersedes tractor muffler.
At some point in time DPF needs to be replaced.
At some point in time tractors with mufflers need the muffler replaced.
I purchased my Kubota L3560 in January 2013. Now 1,600 engine hours on the clock. No DPF problems at all.
Tire wear and tire replacement will cause as many headaches and more expense than DPF/DOC for most long term compact tractor owners who read and comprehend their Operator's Manual. I am shopping replacement front tires now.