Better User Facing Errors

I want to have development type errors for certain users who are logged
into
the system. I recall there are some ips for this, but I want to make
user
based (based on user object in session[:user]). Is there an easy way to
do
this?

Also, is there an OOTB way to get default user-facing error reporting in
production mode to be between “Application error(Rails)” (production
default) and stack trace (development default)?

Thanks,
Nick