I have one, WHEN it works it's not bad.
if you have no, or widely spaced trees, straight boarders and nothing to mow around, you will get along good  - until they send a new "update" that makes you start over with mapping. 
I got mine in March , have had to remap 6 times, at 3-4 hours each. 
Mine hasn't worked in 5 weeks -  due to their last "update."

I've spent more time fixing, it than total hours it would take me to mow for a year. 
RUN AWAY

Crap GPS components, and worse programing. I seldom have less than 23 Sats visible, and it still says NO GPS.
RTK needs rebooted constantly, 
Guys that had it last year, said it was great, this year they have screwed up most of them.
They have 250,000 plus "repair tickets"

did I mention - RUN AWAY?