I have it, nice bag. The roomyness of the main part of the bag depends on how full the front pockets are.
I can easily fit in 2 x spikes + accessories(balls tape etc) in the bottom pocket, all of my clothing in the middle section (including rain jacket, jumper, fleece, jumper, cap) and then in the main section I have 2 x bats (within pockets either side of the inside of the bag), 1 x pads, helmet, 2 x gloves and aero strippers with plenty of space left in it.
For the price of the bag it's very good. Think it's very similar to the old Xiphos bag which was very popular. The bag stands up comfortably no matter how full/empty the bag is.