First is Adam's review:
The Grim Company is a rollicking dark fantasy adventure novel. It moves with verve and pace, fitting more plot than some entire trilogies into its lean 450 pages, and is threaded through with a great sense of humour that pokes fun at some of the conventions of both epic fantasy and the recent eruption of 'grimdark' fantasies in particular.
He awarded the book 4 out of 5 stars.
Niall's review at Tor.com was equally positive (though scoreless):
There’s never dull moment in The Grim Company—even in the middle, where most stories sag. Here, there and everywhere there are extraordinary set-pieces: battles, by and large, but what battles they are! In the interim, there’s murder, mystery and intrigue; a meaningful, if somewhat simplistic magic system; no shortage of snappy banter; and such smooth worldbuilding that I hardly noticed it happening. There’s precious little time to take stock of all this—instead, depth and texture seems to simply spring from the story—but I didn’t mind the immediacy of the overall experience one whit.
In the end Niall concluded that the novel was "pretty brilliant," though he wonders if it might be the last hurrah of grimdark fantasy, apparently now an endangered species. I hope not: I for one don't want to have to go back to the male modelling business, what with its vapidity, shallowness, and legions of women throwing themselves at me...