The old Makita 3310, failed after working for 8 years . Since there is a comparison with the previous one: - the plastic of the 3310 is much stronger, it even rolled down the stairs a couple of times, did not crack, this one is unlikely to withstand such a crash test, although in general we try to exploit such things carefully -about the knife, I wrote in the “flaws” on the previous SO the knife began to look after a couple of years. The conclusion is up to everyone to do on their own 🤷🏻♀️ BUT -3720 is noticeably lighter, more maneuverable, the wheels do not spin when reversing and the height is much more convenient to adjust I won’t say that I’m dissatisfied with it, yes, they used to make it stronger, but this is probably the case with most brands now. I don’t feel enthusiastic, but the device as a whole is worthy. The price for such power is normal. Accessories are available. I can’t advise those who choose a lawn mower for a sports lawn, it cuts even at the highest “3” is still a bit short, for us it’s rather +, it will need to be mowed a little less often, but it won’t make a beautiful carpet, alas)