Congrats on the purchase. I have an MX4800 that I bought new in mid-2015 and could not be happier. It does everything I need on my place. Mowing, plowing, grading mostly.
I am approaching 90 hours and only had 1 regen so far, and if the light would not have come on, I would have missed it. Non-event. Most of my work is at PTO speed and I try not to idle much, so regens are further apart.
If you do a lot of mowing in dusty conditions, do keep an eye on temp gauge. Once the screen starts getting clogged, the temps move up quickly. Last summer I was mowing some tall stuff and noticed the gauge was starting to creep up, and since I was almost done thought I would make the last pass. Within 5 minutes the light came on and got a beep. Not a big deal, but just surprised me how fast needle had moved from 1/2 to 3/4.