I have been using an IntellipH for about a week. The main advantages in my mind is that it is tied to the salt cell. Not only must the pump be running to power the transformer for the IntelliChlor and IntellipH, but the intellichlor must show flow (via its internal sensor). This is a nice safety feature - putting 31% acid into pipes when the pump doesn't have prime is asking for trouble.
The other advantage if you are self-installing, is there is that it runs off of low voltage so you aren't running conduit for line voltage to the unit. The electrical work is just daisy-chaining the intellichlor. If you aren't using an Easytouch or Intellitouch system, it does offer you more control over the intellichlor, as previously mentioned.
So far I like it. Got it for $460 plus shipping.