The A400 Xplor 28 is about as good as it gets in a semi 28ga. Then again, I recently saw a friends Urgartecha 28ga SxS. He paid about the same as one would for an Xpolar.
What do one of those run? I saw a beautiful Benelli in 28ga the other day and all I could think was 'WTF you gonna do with this thing in FLORIDA?'
