It's an expensive purchase, but worth it if you deal with stairs. If I had to do it again, for just pinball I would get the 60" model. I got the 66" and it's a little bigger and heavier than needed. My friend has the shorter one which is more manageable on tight stairs and is also faster.
For accessories, definitely get the big wheel attachment. With it you can roll over grass easily and the load balances perfectly so it's weightless when pushing it around. I debated getting the retractable load support and didn't, but if you mainly use it indoors on flat surfaces I could see it coming in handy as the big wheels are a pain indoors. As for the big toe plate, save the money as I've never used it for pins and it is very heavy. Instead I am really glad I added the magnum crossbar as it makes it much easier to grab when going up/down stairs, and a belt strap. In fact, I wish I had sprung for two as they work well to snug the load up.
I hope that helps.