Considering an HTT. Where do I start my research?

To answer your question about when the Roo's started using the arched roof it was about 2009. I have a 2010 233S Roo & it has the arched roof. It is a subtle arch not a dramatic one like some. We are previous popup owners (28 years) & still enjoy the tent bed ends. Other than an occasional noisy neighbor it can be fun at times to hear some of the night noises (coyotes howling, owls hooting, skunks or racoons rummmaging through garbage, the gentle pitter pat of rain falling.)