Browserify is not maintained anymore. It's sad, but it simply is out of the competition. Also, chances are you can easily find webpack loaders for your workflow where you would struggle to find an equivalent browserify plugin that works and is maintained.
I'd say that's pretty big.
If you want a simple build tool, that works out of the box, you could check brunch perhaps.
Longer story: it's more of a kitchen sink approach that does more out of the box whereas Browserify is more minimal.
Webpack is very config heavy too.
I give Webpack a lot of crap on Twitter about what I see as encouraging bad practices but to it's credit it's developing very nicely.
But if you're happy with Browserify there is absolutely no reason to switch other than tool-chain momentum.