I approach hardware updates like I do any other software updates (especially if the hardware doesn't have any means of getting an outside connection (direct or indirect(by indirect, I mean the printer isn't connect to a router(direct), but it is connected to a computer that has an internet connection)) and that is don't do them just for the mere fact of doing them. Now, if the hardware not having internet connectivity is not a permanent thing, that does skew the thinking here.
If there is something that is needed from an update, then by all means do them (functionality, bug fix and/or security update), but if the sole reason is for just being on the latest and greatest firmware/software update, I personally wouldn't do it. Especially if everything is working as it should.
I firmly believe that updates should be done, but in a controlled manner. While updates have their pros, every time one is done, there is a risk of disrupting the status quo with every update, even if it's one that is worth getting. Updates are very much a double edge sword. Don't want to get too far behind, but always being "bleeding" edge may not be the best either. However, if not totally connected to the internet (either the printer or the computer), the need for updates is less as long as everything continues to work the same.
