I have a Lightning roll out question for those that are fully on Lightning.
We have turned on Lightning for a group of pilot users and have received some feedback that Lightning is more difficult than classic because of appearance (white space and font) and some functionality that is non-existent or underdeveloped. I have created a Chatter group for the testers. In this group, I provided a list of known limitations/gaps and as issues arise, I research them and provide the users feedback on workarounds and/or roadmap updates. We are getting closer to launching Lightning but I am afraid that some users are going to feel like they are taking a step back despite some significant gains we will have. I don't want the users to feel this way and am trying to do what I can to avoid any negative feelings.
How has your company dealt with issues like these? Is there anything that you feel helped users to see the benefits,even though there are still some limitations/gaps?
Thanks in advance for any feedback.

@Michael Lupino@Tom Blamire Thank you both for your feedback.
I think part of the issue is that our entire organization uses Salesforce so we don't necessarily use it in the traditional sense of sales and service cloud. Cases, for example, are used for both external customers as well as our workload internally (technology help desk, marketing requests, building maintenance, etc). Unfortunately, a great deal of the complaints I've received are related to Cases which I know is still under developed.
My other issue is that I do not have a Salesforce champion for every department and they are who we work with for testing. As a result, I know there is probably going to be some gaps I am missing.