I have a love/hate relationship with mine, a 1997 500 model I bought for £300 three years ago. I love the bandsaw that came with it. Apart from it's capacity it seems to be highly rated against other bandsaws due to a lateral thinking design. So read a LOT about the SS bandsaw before messing with it, it's different. Make sure the rubber tyres are good, I've read bad stuff about eruthane tyres and Shopsmith don't ship here. Would be handy to have friends in the states.
I hate the main table, it flexes without much pressure but where else do you get a variable speed table saw for £300? I'm going to work on it in between getting acquainted with the lathe function.
I've had many metalworking problems where the versatility of the Shopsmith saved the day. Get yourself the SS 1/2" router bit holder and you have a milling machine. (Don't use the Jacobs chuck for milling.)
No connection but if you're still keen, I suggest googling "Martins Boot Fair". He's not shy with the prices but if you get a 510 from him at least you'll know it's been checked over and is in good alignment. Means you can start wooodworking rather than machine rebuilding. Not that I've ever contacted him but he seems the type that would spend some time with you going through the alignment procedures.
I know people keep saying that stand alone tools are better but imo the Shopsmith is a stand alone tool. It's the tool that will do most if not all of the tasks your other tools can't do. It compliments stand alone tools well.
I have a Festool track saw that does glue ready cuts so I don't need a jointer but cutting smaller pieces with it is a right pain. Hence the desire to sort out the SS main table and make a sled for it. On the rare occasions I could do with a planer, the SS sander does the job albeit slow and messy.
A big benefit for me starting with a Shopsmith was removing the 'urgency' for stand alone tools. Why settle for a lesser rip saw when a bit of waiting gets me a Festool track saw? A year later I could afford the Festool RO150 sander, an amazing piece of kit. My sil details cars and he went green when he saw what it can do. This year I'm spending my time and money on the Shopsmith and if I don't manage to sort the table out I'll get a good 510 next year and keep this one for lathe and bandsaw use.