I'd suggest "business model changed" is a bit off. We've been authorized dealers for almost every product we sell for some time. As manufacturers make the move to allowing online dealers, we have worked with them to establish relationships. So this really is not a change in business model for us, just another vendor decided to move online.
We still price match and give an extra 5% off so technically still have the lowest prices, we have an easy to use 60 day return/120 day credit policy and more selection than a typical local dive center.
Having spent the last two weekends mystery shopping 9 different LDS's, I can confidently say in my area that we have the best selection, best prices and best customer service.
I look forward to hearing feedback from others though and if anyone shares anything actionable, I'll be sure to pass it along to my manager for consideration.