The current GN Pro Performance would be the perfect bag in my opinion if it was slightly bigger, they have addressed the sizing issues and added some cool features like a flip top zip-up lid, making it incredible.
The M&H is just another duffle bag really. Most duffles are let down by their drawstring closure which is less secure and does allow the rain to come in rather easily.
The GN range of duffles is unbeatable for 2014. The impact is sizeable but basic, with a drawstring. The pro performance is an improvement on the current design and the GN1000 has all the bells and whistles, top quality.