[cups] lpadmin vs. /etc/cups/lpoptions

[Arney]

Dear CUPS users,

on a multi user system, I used to set the default destination and the 
printer default options like this

sudo lpadmin -d LaserJet # Modifies /etc/cups/printers.conf
sudo lpadmin -p LaserJet -o HPSpecialOption=SpecialValue

This seemed to be broken to me today, but then I found out that I 
accidentally had used

sudo lpoptions -p LaserJet -o HPOption=HPValue
sudo lpoptions -d DeskJet  # Modifies /etc/cups/lpoptions

last week. So I learned about /etc/cups/lpoptions.

Questions:
1) A little experimentation indicates, that the settings in 
/etc/cups/lpoptions will have precedence before everything set using 
lpadmin. Is that true?
2) Is /etc/cups/lpoptions the preferred way to set system-wide defaults?
3) How come there are these two ways? Historical reasons?

Thanks

Arney