I echo the suggestion about taking time alone in the various models. Take along everyone who'll be regularly camping with you--you'd hate to buy a particular model when it was just you and/or spouse looking at it, then have to live in it with a batch of kids and the dog.
We were set on buying an A122 after our first look at the two models the dealer had at a sports show, and when we went back the next day to buy it we took about an hour to sit in each model and picture ourselves using each one according to our camping habits and preferences. As a result we ended up buying the A128 and haven't regretted it...(we're older, we read a lot, and so a variety of comfortable seating was a big deal with us). Your mileage may vary, as they say.
Whatever you decide, I don't think you'll go wrong with the Hardside line from Forest River, either the Rockwood or the Flagstaff sub-brands (they're identical). They're well equipped for the price and I think nicer inside (and less expensive) than the other two major brands of A-frame campers.
A suggestion before you sign on the dotted line: spend a lot of time crawling around and inspecting everything from fit-and-finish issues to entry and exit points for water/gas/electric services. Take a flashlight and look into everything. Lay under the unit and inspect the underneath carefully. Note down everything you're not happy about. Check how the wall and ceiling gaskets fit, both open and closed. Tell the dealer the specifics you want fixed before you'll take delivery and point them out to him/her. Recheck when you take delivery. I'm not saying these units are badly built, but RV assembly issues are an industry-wide problem; there are problem areas with all brands and models. You'll want to feel sure you're starting out ready for the road. Then enjoy the heck out of it. Come back here and show us pictures of your trips, ask questions, share tips. Welcome to the family!
It's never too late to have a happy childhood!
Lee, WU0V, and Courtenay, N0ZDT
2011 Rockwood A128
2000 Silverado 1500 pickup
60W solar system
2000W inverter generator