I think most investors should have a fixed dollar amount In their head that they want to invest. Say $5k and then they just see how many shares that will get them. If the price rises they will just buy fewer and if it falls they buy more.It's like I don't mind if gas prices go up or down. I always fill for $50;-)
The Main reason for the 4S continued popularity is it's the only iPhone left with a dock connector. So if you are heavily invested in dock accessories (car, stereo, work etc.) you'll buy the 4S in order to avoid lightning adapters everywhere.
Looks like the Analyst didn't realize that under a contact there is No 10% Sales tax on the full retail price (650$) but just on the downpayment of ($199). Thus he is overestimating the TCO of the 2y contract by $45
I think this is a part of a much broader Siri enhancement. Apps will get an API to plug in to Siri and be voice enabled: e.g. Asking Siri to check the best price for an airline ticket will pull up the answer from eg kayak app or expedia.