Thoughts on Navien NCB 240

I was hoping to get some perspective on the performance of the Navien NCB 240 system. I am a homeowner in Massachusetts looking to replace an old Hydrotherm gas boiler and standalone hot water tank. The NCB 240 looks like a great fit, but it's been hard to find any reviews on its performance. Hoping to get some perspective on whether this system can truly heat a 2,000 sq ft house in a New England winter while running two hot showers and a dishwasher at once as their marketing suggests. (Note: We are a family of four.)

I'd be grateful for any feedback on the product's performance and total cost of ownership.

Thank you,
Bill