...Fastfind runs around $250...
 is not much more --- $272.  They're both good, but the ACR unit "feels" better to me.  I have no objective rationale for thinking that.  
I had a FastFind in my flight bag and I currently have an ACR ResQLink tethered to my vest.  My neighbor who takes his sport fishing boat off-shore has what was formerly my FastFind.  When it came time to reregister I let him put it in his name.