Dan,
Depends on where you are sailing. I sail on an inland lake and use a GPS  for 
compass and knot meter. Don't really have much need for a compass however,  
but it's nice to know where I'm going. I have a windex on top of the masthead  
antenna and I use the centerboard as my depth gauge. If it drags, I'm getting  
shallow.
I'm a firm believer in the KISS system. Always have been. Fewer POS's to  
break. I'd rather be out sailing than worrying about why my knot meter isn't  
reading properly, or is it?
 
Rummy