One difference between these two models is the bass output. Naturally a 7.5" dedicated woofer will move more air than a pair of 5" midwoofers. Depending on how loud you play the speakers, this may be an issue in a condo. Both are strong designs, so I'm sure you would be happy with either of them. And while there are a few other differences, I think the most important for you might be the amount of bass the speakers output.
If you have additional questions, perhaps you can email me at Jim @ Salksound.com (without the extra spaces). I'd be happy to answer.