I've been using it for several years. It is a 'permanent' address in that should I change ISP's there is no need to notify everyone with a change of address. Only one change at ARRL. Of course that address is only used for 'good' contacts and not posted anywhere for the spambots to see.
There has been no problem with the arrl forwarding I'm aware of. They may have been making some changes last week but I think it only pertained to the staff, with
callsign@arrl.org addresses.