There is some truth to the "staying dry" point.
A lot of it comes down to design and materials.
A cheap dome tent with a fly over the top vent area only, single wall the rest of the way down, is not going to keep you dry. There may be a better quality dome tent with better quality material than what you will find at Walmart, but it will cost you.
Then you get in to the differences between 3 season and 4 season tents. Most "3 season" tents, in my book, are "1 season" tents - warm weather only - and are nothing more than a bug net "tent" covered by a rain fly, if you so choose to put it on and not sleep directly under the stars. All that mesh doesn't do much to insulate when you are in cooler weather.
4 season tents have no mesh except for window/vent openings. These are true double-wall tents where you have a solid tent and a weatherproof rain fly on the outside.
The main tent I have is a Mountain Hardwear Hammerhead 2 that is about 10 years old. It is a very unique tent in that it is a true double wall tent - if you zip in all the paneling. It was marketed as a 3 season tent, but with the zip in panels it is as good as a 4 season tent in the cold (and its been in the appalachians with temps around 0deg F). The drawback to this style tent is that the fabric plus the mesh, for those double areas, does add weight. No two ways about it. The protection and flexibility, though, is a huge gain - a gain not very common in the 3 season tent class.
When you look at "design" - you can look at name brands vs lesser "quality" brands (big box store, general consumer type - like the kind you find in the camping isle at the general store) and gather that a particular design may be similar to a name-brand, but 1/3 the cost. However, material and durability is a factor as well. Higher quality materials are probably going to keep you dry.