The reason there is not much information regarding the Summit is because it was marketed by Thor industries, a large parent company producing several lines of Rv's & of which produced the Summit from 2006 through 2008 models years only. It became MVP RV beginning with the 2009 models & no longer part of Thor Industries.
The Summit appears to me to be a very high end TT & depending upon your use has some great features including the aluminum construction, heated tanks, ducted air etc.
I think it boils down to, as always, the condition of each unit & floor plan you prefer.
On another note, The Craig's List add for the Jayco says warranty not included with listed prices. I would carefully consider the add on cost of that available warranty & any applicable deductibles. I rather doubt it's worth the cost.
