My enthusiasm for the IP7250 doesn't go as far as recommending it over the older models. I have 2 IP 4500s in use and one IP4500 packed away and one other print head in reserve. For me the IP4500s were the best everyday printers Canon produced. However, I was tempted to try the IP7250 as a bit of a challenge. The refillable carts I'm using have ARCs that don't reset if you take them out of the printer or on startup. The only restriction is not to refill a cartridge until the printer shows it as empty.
So far I've refilled the carts about 5 times (OCP ink) and no problems so far
However, your point about not worrying about buying and storing older models may well be valid. Certainly I've gone from a glass half empty to glass half full mode since getting the IP7250.
Perhaps I should start hoarding some IP7250s in case Canon next bring out another printer with even more restrictions.
On second thoughts, perhaps not. I'm running out of storage space and I've my marriage to consider.
Indeed, the main problem is to find dye ink with a reasonable fading resistance (and pigment ink with reasonable gloss difference ).
One of the reasons we have so many printers.