It must be like anything else: buying a factory-reconditioned item from a reputable manufacturer should be fine, but anyway be covered by a warrantee for at least a year.
I don't own anything trade-marked with the "i" prefix, but I am happy with my factory-reconditioned DELL PC.
I have had problems, but they were caused entirely by Microsoft, not DELL.
..........
(Mickeysoft changed its OS from WIN-10 that DELL had installed, to 11 without my permission. In doing so it --
-----interfered with my photograph collection, removing their directory structure, and even losing some of them completely and placing others on the MSN/Bing link -without authority;
----barred access to my extension hard-drives; and
-----replaced its own, long-established and efficient file-organising system with a very slapdash version awkward to use.
It also seems to have cut bits out of its own "Excel', I found when I tried to create from new a new edition of a particular graph it had let me create a few years ago. I believe it has also scrapped its "Access" database-builder, though I no longer need that anyway.
Basically the company has lost its way, so is incapable of providing anything new and worthwhile for serious use, but just tinkers around the edges, and spoils what it had already offered and had worked well for a long time.
That though, is all to do with that monopolistic shower in Seattle, not the computer manufacturer.)