Advisors, however, don't often present their value proposition adequately, and lack an “elevator speech” that enables them to tell plan sponsors how they stand out from the crowd.

In addition, the factors they might want to emphasize can vary depending on plan size.

The study found that, for smaller retirement plan sponsors with less than $25 million in assets, that trifecta of education, service, and cost was more important than for sponsors with $25–$75 million in assets, who confirm those values are important but say they have broader needs.

Larger sponsors, the study found, are more likely to want help from advisors with additional services and capabilities, specifically advice on plan design, investment selection, fiduciary support, and help with other benefits.

While 93 percent of sponsors who work with an advisor say their retirement plan advisor is valuable, especially when it comes to customer service, advice on investments, and problem solving, that doesn't mean they think advisors are perfect.

There are several areas in which plan sponsors say their advisors can do better, including educating employees in group meetings, providing insights on how to lower overall plan costs, and providing information on new developments for retirement plans, according to the study.

Smaller employers with plans of less than $1 million in assets say they need help in keeping up with new developments.

Interestingly, although employee education and advice is “universally valued” by employers, and many say they want more frequent educational sessions for employees, advisors have their own criticism: that employers are not always willing to make time for their employees to participate in educational meetings.