To answer some questions, Dometic redesigned the interior air box being used with the Blizzard NXT to reduce air noise by elimination of sharp corners, louvers, and so on. The redesign does a nice job quietly handling the increased CFM air flow.
I had two 15k BTU units installed because the 13.5k were not available at the time. It was a good move for me. I pressed a little cleaned out Keurig type coffee cup over the rear/bedroom temperature sensor to keep the direct cold air from blowing onto it, allowing the rear unit to stay on longer and cool the entire AS with one unit. I tend to run the A/C unit that is furthest from the area I'm spending time in when only 30 amps are available. If you check the specs closely, I think both units can be run at the same time on 30 amps if nothing else is drawing on the line however I haven't tried that yet.
There are no decibel specs posted for this unit, however they definitely are noticeably quieter then the Penguin I or II.
There is a drain kit available as an add-on. When installed, it easily connects directly to the existing AS tubing. All things considered, if you're planning to install a Blizzard it would be best to have about 4 to 6 inches of extra tubing and a connector fitting (90 degree) to eliminate any possible kinking. The only thing I don't particularly care for is that the kit is made of white vinyl plastic, so it is more visible. I plan to paint mine black.