I'd say to try sewing on all of them. One of them will speak to you, as another poster mentioned.
I was all set to get a Bernina. Sewed on them at several different shops. Just wasn't feeling it. I couldn't intuitively do *anything* on it! Finally, at the last shop....the saleslady says, "Oh, honey. That Bernina doesn't like you!"
And that was it; I just hadn't been able to articulate it. I didn't really like the looks of the Bernina, it was too tall, too hard for me to figure out, and it didn't like me.
OTH, the BabyLock Crescendo just resonated with my soul. I could do anything I wanted intuitively. I didn't have to get out the manual to study first. Plus, I just liked looking at it. And the sound it makes when it turns on is so cool. Sometimes I turn it on just to hear the sound.
The Bernina - I had to struggle
The Janome - was ok
The BabyLock - made me smile
Your test sewing will do the same for you....one of them will say, pick me! Good Luck! And may you always that great big smile when you sit down to your new sewing machine.....