I'm really surprised a Brother dealer would make a statement like that - Brother and Janome are both made by the same manufacturer, the biggest difference is looks and price, their functions are almost identical.
If you want to check out reviews on sewing machines, go to
http://sewing.patternreview.com/.
I have bought several Brothers from Walmart and never had a problem. Sometimes you do get a lemon though, but that can happen with any machine.
The Brother CS6000i and the XR9000 have good ratings. Look for them on Amazon, they have really good prices. Janome has good machines, they are a little more expensive and I don't think they have that nice extension table the Brother's have, but they also have a good reputation.
My Joanns is now selling Vikings and they have a good reputation too. Stay away from the new Singers, they are suffering from poor construction these days - plastic parts covering metal gears, have a lot of "break apart" issues.
If you see something you really like, I'd check out the reviews and ask the board members if they have/had one and what they think.