10-15 miles per week? I would personally just go with the base Sirrus. That is what I have, and once the weather stays more...constantly warm and dry...I ride 30+ miles per week on that bike. I dont feel a need for a better bike, and I have a full LX mountain bike which does shift smoother, but I dont find myself shifting as often on the road, either.

If you find the urgent need to spend money, The Elite is worth it. I can tell you from experience that the LX rear derailleur will shift wonderfully. The Extra $230 gets you 9spd instead of 8spd as well. Another point to consider is if you ever want to install fenders (they actually look pretty nice on the Sirrus, mine has them), the sport and elite have "mini v-brakes" which will need to be changed out to full size v-brakes so fenders dont interfere with the brakes. The base model has full size v-brakes and I have plenty of clearance with fenders on. Just thought I would throw that in there. Fenders are wonderful...Rocks dont hit the frame or fly up and hit me

Specialized is an awesome brand. I have a Sirrus currently, and had an Allez road bike. Have not had complaints with either, the Allez had a 24 spoke radially laced front wheel, and once I properly tensioned/trued it, it did not go untrue, even under my 230lbs pushing the bike.

OK, If its giong to be your only bike, getting the 9spd might not be a bad idea. 9 spd is still the mainstay of mountain biking, and components are plentiful. 8 spd is still out there, but harder to find real quality stuff anymore. So, maybe the Elite is a better buy. Besides, once you start riding the Sirrus, you will want to ride it more and more....