I guess my response would depend on your answer to a couple questions...
Are you a fair weather camper or do you like camping in the spring and fall also... If you do Avoid tents with screening instead of fabric for large parts of the wall...
How long will you camp for... A weekend, or a week... If you want any room in your tent to move around go bigger than your needs...
Personally I do not like the tents with the screens attatched...We have a 10 person tent with 4 removable walls... Then we set up a screened gazebo right in front of the door (line up the doors). I do not and will never trust the "rain flys" they don't do anything to keep moisture out... So we throw a tarp over the whole shebang (tent and screen tent)and stake it down... In our tent we put a portapotty and put up one of the walls, we have a portable closet, and room for beds for 5, a dog, and extra space. But we camp for more than a week at a time with 3 young kids...
Why is it that I do not like the screen attatched? You pay a lot more for having it attatched... They are typically SMALL, and if they rip in an unfixable place you have to replace the whole tent... Its cheaper to replace a screentent often and spend that extra $ on a great tent...
We recently bought an Eureka tetragon tent and took it back the next morning... Even though the "rainfly" goes almost all the way to the ground the sides on 2 sides were screen... Any and every breeze came right thru. (and the zipper cover was ripped)
Buy what you like... Then set it up and try it out in your back yard... If you don't like it take it back... If you do, stay in it again... (kids will LOVE the trial period)
Look over EVERY inch of the tent inside and out... Even if its made by the best company it can still have flaws...
We have had some awesome tents we bought at walmart, and some bad ones... Just like we have had awesome tents from dunhams and bad ones...