Nothing wrong with a good boar brush. The problem is cheap boar hair is, well, cheap and therefor what they use in the cheapest brushes. But quality boar hair in a bush, like the better Omega brushes, is quite nice. It's just different than badger. The individual hairs are thicker giving it a different feel. And because of this the loft doesn't hold quite as much water and lather so they can take a smidge longer to lather. Also, they don't bend or flop as much so you wont get the ultra soft feel of a uber nice badger brush.
That said, some people who favor soap prefer the boar brushes for this very reason as they feel they pick up the soap better.
If you want a brush that holds lather like no other, whips it up faster, and has that soft feel to it go badger. If you are ok with another second or two to build lather, and prefer the feel of a brush without as much give, and want to save some cash, go good boar.
For 20 bucks, you'll get a kick ass boar brush. For 20 bucks of "pure" badger, you are getting the badgers ass whiskers and a loft that is probably trimmed even meaning it will forever be scratchy and annoying. I love my best badger EJ and still feel it's the absolute best buy for a badger brush, but if I only wanted to spend round about 20 bucks I'd take a good boar long before I take a subpar badger.
Parker is also good stuff, but I personally actually don't like silvertip. It's nice on occasion but it's usually just to floppy for my taste.
