The implementation team has in-depth knowledge of the product. Their deep product knowledge, understanding of best practices, and track record of effective execution. They have not just started their implementation practice. They have real world experience with planning, consolidation, financial reporting, or whatever the buyer is focused on.
Scenario: A large-scale manufacturing company decides to invest in new CPM software to streamline their financial reporting and management process.
Solution: They go for a software vendor that provides an experienced implementation team with references in manufacturing. The team they select is running only a few concurrent projects and is ready to kick the project off within 2 weeks.
Interview the consulting team to make sure they have the knowledge you require - specific to your industry if possible. Make sure they've been working with the specific product that you are evaluating, not something similar.
Be wary if the sales rep for the consulting company is unwilling to introduce you to the consultants. They may be buried in work, or they don't exist. Either of those scenarios is bad for you.
Be clear about who you will be working with day to day. Sometimes you will be assigned a Project Manager, but they only manage sxchedules and arrange meetings. They have no material product knowledge. If you'll be working with a functional consultant most of the time, meet that person. Do not allow your requirements to be treated like the game “Telephone”.