I don't know why (maybe the houses on top of the course), but I just don't get Isleworth honestly. Played there during a trip that included Old Memorial and found it to be far superior to Isleworth other than conditioning as Isleworth was pretty much perfect. I think its a great residential course if cart paths are your thing, but not a top 10 in the state. Haven't played Lake Nona, but the pro I played with there said it was a better course as well and I don't see it on many lists.
Dustin,
2 disclaimers to my ranking of Isleworth as I can't disagree with anything you said...
1. I haven't played many others in the state that would no doubt take its place (ex. TPC Sawgrass, Black Diamond, Old Memorial, Calusa Pines, Pine Tree, just off the top of my head)
2. It is a wonderful experience to play Isleworth. The gentleman that I play with there has been there since the place opened and knows everything about the place. It's also cool to run into Ken Griffey Jr, Paula Creamer and others while you're on property. Just my thoughts