That’s a loaded question, because I have both printers and neither of them are hard on print heads, the 4500 is tens years old and its current print head is six years old, the previous one died when someone ran the cyan ink dry and didn’t bother to notice.
The 4700 is six years old and still on its original heads, it’s also been converted to use CLl-8 carts and works trouble free, it’s not as well constructed or as tough as the 4500 but it print far better and faster than the 4500 does.
The 4500 ran great with a CISS where as the 4700 hated using the CISS and gave nothing but trouble but works far better now with the new bigger ink cartridges.
So does this go anywhere near to answering your question.. ?