That sounds pretty appealing. I have never had a good look at a 210.
It cruises about 10kts slower than the cirrus on the same fuel burn. But its larger inside, comfortable, can haul mom's bags, and mom does not have to climb on the wing to get in and out. Plus it would be less expensive to acquire than a cirrus, i'm guessing maintenance would be about the same on both aircraft?
Plus its a cessna, he has lots of time in cessna's and his 172 ownership was a pleasant experience, he sold it for more than he paid for it and never had any major failures or unexpected repair bills.