I love the "silent" part, love the thought of a long term payback... but I have to pay this year, don't get the kickback till next year, and that means a 14k out of pocket investment immediately.
I'd rather throw that money into my audio, I enjoy music today LOL!
Spray foaming... do I need that in Wisconsin? I'm more worried about a cold -30 than I am about a hot 130.
Spray Foam absolutely. It makes no difference which side is hot. The bigger the inside/outside difference the better it performs versus regular insulation. The main deal is that it is a super good way to block air infilatration. It seals up every little nook and cranny. Also there are no gaps and no getting over packed. The colder it gets, the more pressure the warm air rising in your house will exert on the walls/roof areas of the upper floors, and the more negative pressure it will exert on the lower parts of the house. This is where spray foam really excels over conventional insulation, holding the inside air in and the outside air out.
Also, it is very nice and neat and clean. Fiberglass has all that fiberglass dust and itching, blown in stuff is sloppy. I am telling you, the spray foam is clearly superior. You will really be thankful when you head up to the attic to pull wires or whatever and it is a comfortable place to work and you have a clean shot at the attic side of the ceiling. And you can put temp sensitive stuff in your attic. You can have water pipes up there, and unlimited storage.
I also think it keeps the bugs out. We have lots of creepy crawlies here in TX and almost nothing gets in the house. This is especially nice regarding the scorpions.
You might consider an air exchange unit if you do foam. Foam tends to seal up so well that the inside air can get stagnant. The air exchanger exchanges inside air with outside air over a heat exchanger so you don't lose your hot/cool.
EDIT: I also went be surprised if you couldn't talk the geotherm HVAC guys into spotting you the tax credit until you actually get it.
Also, if you finacne right it wound't cost you anything extra at any time. Say you finance the $14k over 10 years at $120/mo and the unit saves you $120/mo in fuel. It's a wash, and then after 10 years its just gravy.