I have had both the base S and the SV with convenience package and can say I understand the reasoning behind either decision of purchasing both.
I bought my base S for the simplicity and the "less to go wrong" with it about the car and after driving it for 70 000k the things I wished I had were the door locks and a better drivers seat.
Then to be honest with all the incentives going on at the time plus the deep discount Nissan Canada gave me to buy I was able to get the locks and seat plus a bunch more stuff that the SV /w/con. pkg offered that year for barely anything over what a base S cost it was really a easy decision.
That being said there are things I don't use on the SV very much like the back up camera and the adjustable mirrors ect.
the blue tooth I only use for phone calls and to use the little symbol to tell me if my lost phone is in the car lol.