If the chain is "jumping", call the shop to have it adjusted correctly.
The Sirrus is a great bike, and even minor adjustments can make a big difference. Like bars, stems, seat and seat posiition, etc.
You will really like it once it is dialed in for you. It's really easy to go fast on the Sirrus.
I also have a Crosstrail, by Specialized, and it is more comfortable, but it won't go like the Sirrus..... The Sirrus is not uncomfortable, just not as comfortable as the fat tires and suspension of the Crosstrail. The Sirrus is lighter, and faster, no doubt about it.... It just won't carry as much as the Crosstrail.
Don't second guess yourself - you made a great choice! If the seat is uncomfortable to you (and you have to give it time to adjust to it) Selle AnAtomica has a good sale in the fall, and it is a wonderful saddle. I use their NSX and it was comfortable right out of the box, and stayed that way.