I've worked in a lab with rats, (behavioral chaining study... no rats were harmed, they were well socialized and well treated... we played with them for hours before doing any work since to be honest, if they're afraid of you, they won't DO anything for the study. The rats were adopted out at the end of the study as well, mostly to the researchers who worked with them, oddly enough!

) and we used similar housing. I'm also currently owned by two pet rats that I keep in a Martin wire cage.
There's absolutely no comparison. The rats in the wire cage are a million times happier with their home, and I would never recommend a rat rack for anyone interested in the long term happiness of their pet.
Advantages of a wire cage:
More circulation of air = healthier rats
levels to climb
room for more toys
able to see out into the "world", which they enjoy
You're able to see your rattie play, which is a BIG perk to being a rat owner
It's not even a comparison, honestly. Rat racks are not for pet rats.