They say that about Ibanez because of the way the neck on the guitar is made. They are very thin which makes it easier on the hands. And it also has to do with the radius of the fingerboard, as they are not exactly flat.

Wood is important in a guitar bacause it is going to shape the whole tone and sustain of the instrument. Now there is a rumor running around that the heavier the wood, the better the sustain. That is completely untrue. Some woods like alder, basswood, and swamp ash, are quite light and sustain quite well. Also a few other things that effect sustain are things like tremelo systems and how they are put in. Personally I like the tremelos that are flush to the body versus routed into the body. Also the way the neck joins the body can affect sustain. A neck-thru guitar will (in theory) sustain better than a bolt-on neck.
Also different woods sound different. Mohogany will sound warmer and darker sounding than maple. Maple is quite bright sounding. This is why you find a lot of guitar that are made of mohogany usually have a maple top. Not only are the beautiful but it brightens the whole tone of the guitar.

Also a guitar that has a bridge where the strings are strung through the guitar instead of the bridge will also sustain better.