Keep in mind, the time period that at least the first few books of the "How Few Remain" series takes place in a time when racism was alive and well, and the norm for the majority of the world.
The writer shows various characters as smart, capable and clever, regardless of their color or ethnicitiy. This tends to counter the cry of racism, in my opinion.
That being said, while I enjoy his writing, it tends to be a bit repetitive. And his usage of stock phrasing gets be a tad heavy handed... yes, we know he's a fair skinned redhead, yes we know he's gonna put zinc on his nose, yes, we get that he would prefer to be in a cooler cloudier clime... is it necessary to mention it every time the character is active?
Stirling has the same issue, imo. He has a handful of stock characters (the wise and bad ass foreigner, the tough kick ass lesbian, the scheming badguy who revels in his villainy, etc) but I still find him enjoyable. The counterpart to the "Isles in the Sea of Time" series is the Emberverse series. It takes place in the rest of the world after nantucket has gone back in time. All high energy processes stop (sort of, fire still works, body electro-chemistry functions) so gunpowder, electricity, steam engines... all non-functional. Fun, but by no means should it be taken seriously.