I just set up 5 locations with those miserable little things. They can appear to extremely complicated because Nortel, as usual, provides the worst documentation on the planet for their products.
In fact, when you finally get familiar with them, you find that most of the stuff they are capable of doing, you require very little of it to set up a vpn tunnel.
I can set one up in about 10 minutes now but as you say, figuring out the first one can take days if not weeks. They are cheap and good for up to 10 tunnels but after that, Contivity is the way to go. Cisco is ok too and their documentation and website is far superior to Nortel.