I can't find the VQ 5100 when I google it. Are you sure it's not a different model number?
Personally I love my Janome. It's an 8200 and I love the 11" throat, auto cutter, smoothness, quietness, intuitiveness,
and it's a dream to FMQ on.
But I'm sure the Brother is a good contender. I would check throat height as well as length on both. It's amazing the difference an inch or two of space makes.