This is the International Show? If so, it's a new site so I'm not sure - it moved to Cinci from Chicago (much to my dismay). The one in Chicago had tons of vendors and I can't imagine that the bulk of them didn't follow the show. Most machine vendors were there, and I know for a fact Janome will be there because my LQS runs the Janome booth (say hello to Chris for me!). And yes - you could try the machines including the long arms. There were some vendors offering good deals, some were set at regular prices so do shop around. More than a few vendors with the weird and wonderful stuff we don't typically find in quilt stores like Japanese silk panels (still wish I had picked up a few of those!), bolts of silk and wool, ribbons and threads of all variety.
Enjoy!!