Great question. I apologize for not noting that in the original question.
I am speaking about the Web Console. It is not a deal-breaker by any means, but I have had some complaints and if I can hard-code the "DOMAIN\" part to the beginning of the Username field, it could cause less frustration for the end users thinking that their credentials are wrong.
SolarWinds solutions are rooted in our deep connection to our user base in the THWACK® online community. More than 150,000 members are here to solve problems, share technology and best practices, and directly contribute to our product development process.