With so much on offer you really need to narrow down exactly what it is you want in a hotel - what is non-negotiable and what can be compromised on.
As heresmyreply said, the AI complexes generally run along the lines of offering everything within the resort and they don't expect people to be making daily jaunts into the city. Therefore it doesn't matter that they are a distance away.
If you are looking for organised entertainment, easy alcohol access, lots of food, activities, spa, pool etc then AI is great. Otherwise you could look at hotels in the Ville Nouvelle that offer half board etc but are closer to the main attractions.
Another alternative is a hotel or riad in the medina where you would have the option of eating an evening meal there or outside in a café/restaurant etc.
If you click on "How to choose a riad" under Top Questions on the right of the page, there is a list of things you might want to consider. It primarily applies to riads but it can also apply to choosing a hotel, in terms of thinking about mobility issues etc.
Edited: 8:56 pm, July 10, 2013