Here's a cool resource I was just introduced to: G2 Crowd. As the headline suggests, it allows you to review and compare software across many categories including, yes, accounting.
Once a product gets 10 reviews, it gets placed on a grid, like so:
G2 Crowd put out their first report on accounting products just last week, so if you or someone you know wants to drop some coin for the report, it's contains information on hundreds of reviews.
In the Accounting & Finance categories, there are reviews on Billing, ERP, Payroll, and Time & Expense in addition to accounting. Vendors and users alike will benefit from the information on this site.