this website gives more details on the Roberts 370.
Bruce Roberts International Australia. Boat designs plans kits and boat building books
Don't actually know anyone with an Roberts 370, the Roberts 38 is a lot more common. Heaps of Roberts designs here in Oz.
Sailingdog gives good advice on steel boats. I think maintenance would be about the same, however with steel you really need to keep on top of it, otherwise a little job quickly becomes a big job. Fibreglass can be a big more forgiving, however in the long run it is probably about the same. Just depends whether you like being covered in fibreglass dust or metal flakes / rust