1) Big and small orders treated the same - lots of orders are around a dollar forchrissakes.
So they let bots spam their order book with 0.01 BTC orders until it crashes entire trading engine; sweet I can't wait for the next "innovation"
The MtGox innovative concept of lag -- I don't consider that as a plus.
They seem to have a function that allows traders to enter uncovered offers, for example if you have one bitcoin you can enter an offer to sell that bitcoin, and at the same time offer to buy a bitcoin at another price. So for each trade, they have to walk the complete order book to activate the offers that are now covered. Nice, but not essential. I hope they just stop doing this, and focus on speed.