linking external reviews
Since you "don't have the staffing or bandwidth to implement other data sources at this time", how about letting users to link reviews from professional critics? Because Xperi has downsized its editorial staff, you've allowed users to write user reviews. But most users aren't as eloquent and as knowledgeable as professional critics, so many user reviews aren't professional quality. Moreover, user reviews are more likely to be motivated by favortism or by personal hate.
By linking to external reviews from professional critics, Allmusic would still be the one-stop website for users to find professional reviews despite fewer being penned by Xperi. It'd actually internationally expand Allmusic's user base, because Xperi's reviews are limited to English and about English albums. Allmusic has a great need for professional reviews in foreign languages, especially ones about albums in foreign tongues.