I am in the process of purchasing my second Magna, which is a 2003 TL ES. I'm going from a VB Commodore to the Magna. I have to say I love my old Commodore, but the Magna is so much nicer to drive.
However my 1st Magna I hated. A 94 TS I think. It was so slow. It was comfy, but I couldn't get over how slow it was. So I swapped my $500 Magna for my Commodore. Now selling the Commodore for a deposit for the Magna. Love it.
I bought a 2005 Magna wagon with 143,000 in Feb 2009 privately for $8400 and as at Oct 2009 have now done over 30,000km. The car is solid and roomy and has enough power for safe overtaking. The 4 speed auto is a little bit twitchy and seems to drop down a gear with little pressure on the accelerator, but apart from that no other problems. These cars are amazing value for money - equivalent Toyotas cost thousands more. It's a bit of an ugly car but the price is low enough to compensate for shortcomings in this department.