I have not found a bad anchorage any place the in Key Biscayne area, just different. Key Largo area is nice. I don't remeber the draft of the Hans Christian. You can cut through Angle Fish Creek during slack tide. Watch the charts and water.
It really depends on which way you expect the wind to blow to make a nice night rest. I usualy stay a little farther south. Key Largo and below. I did stay at John Pennycamp State park. Nice on the Bouys. To much traffic at the dock's. Can make reservations. Lots of bitting bugs. Cow Pen Harbor is nice as well.
None of the guides are bad. BlueWater Books can give you some of the best.
Check this site out for new data -
http://www.cruisingguide.com/cruise-news/wc-florida.asp