I think the Lore Bard is utterly fantastic, both as a single-class and as a multi-class character. The abilities are awesome and appealing for modelling a wide range of concepts, particularly if you're flexible on the fluff of Cutting Words.
The Valor Bard, on the other hand, suffers from the problem that its signature ability, Battle Magic, comes online very late. Combat Inspiration's appeal is limited by its horrible action economy. Extra Attack on a full spellcaster is nice, but Bard lacks spells (particularly bonus action spells) that synergize with it: on any given round you can be a warrior OR a spellcaster, but you can't really use one to enhance the other (at least not until Magical Secrets comes online at 10th). There are ways to make the subclass appealing at lower levels (e.g. adding Paladin 2 for smite, or focusing on grappling), but the subclass lacks the versitility of its sibling. As a result, I find Valor Bard to be a more useful tool than Lore Bard only for modelling certain specific concepts, and thus I consider the former somewhat unexciting. The subclass isn't bad or underpowered, but I'm going to pick Lore Bard for 9 concepts out of 10.