I have an 07 too.. I talked to dealer about it and they said as per GM the range is 50 ft, which i think is kinds lame because i cant start it from my office building as i park at the end of parking lot. There is another post where someone mentioned that remote start worked for them in a building where the car is not in sight and they advised to change the battery .. which I did and first couple of time after that the remote start worked like a charm from far away too.. but then back to same range. I bought 5 batteries from amazon for 3 bucks.. and i think it was free shipping too. I wanted to try the new fob but am not sure how the kep will work with it .. i am sure if we buy it frm dealer they can make the keys but dont want to spend that kind of money just for fobs..
there are actually a few other alternatives to strictly dealer for purchasing key fobs. i havent personally had any expirence with this one, but i do know that the local locksmith for my area can make the computer programmed keys for benz, bmw, licoln and maserati. i cant think why caddy would be off the list. you may want to call around and see if any of the smiths in your area can do it. i know a 400 fob for my bros lincoln cost 230 programmed this way. just my two cents.
The trick to it is you MUST get an STS fob...even though the DTS fobs look the same, they are not the same. Only STS fobs will work. If I remember correctly, you can verify that it is an STS fob by looking for the key release button...the DTS fobs don't have this.