I've had Volo's Guide to Monsters for months now, but I haven't really considered the new races in it and whether they have a place in my Land of Azurth campaign. My consideration of the core book races was here, though some of those (like the Dragonborn) I've reconsidered since. It's always theoretical until they actually show up in the campaign.
Aasimar: Humans empowered by guardian angels reminds he a lot of the Golden Age comics concepts like the Marvel family, but also Johnny Thunder, and Kid Eternity--all very appealing. Of course, their opposite number the Tieflings have been reskinned as Demonlanders.
Firbolg: These guys could be used as is. I might go less fairy tale creature and more hairy hominid with them and reserve them for the Country of Virid.
Goliath: These guys will live in the Dragonspine Mountains and in the desert Land of Sang.
Lizard Folk: There are certainly Lizard Folk, but I haven't worked out their deal exactly and how they differ from the Dragonborn.
Tabaxi: One of the things insisted upon by characters within the setting is that there are no Cat Folk--except that one of the PCs has met two! This is one of the mysteries that may play out in the campaign.
2 hours ago