https://www.bitfinex.com/pages/feesThey no longer have any 0.15% fee. The difference is not between limited orders or market orders, since everyone could use limited orders to buy at market price, but if you inserted your order in the orderbook before the other part.
If you insert a limited bid order at a price under the best call order, but in the middle time someone inserted a call order below your price, you end up being the market taker and paying 0.2%. Otherwise, you will pay only 0.1%.
In the end, Bitfinex fees are at the most equal to BTC-e. Normally, they are much better if you are a market maker.
And on LTC (and DRK, even if BTC-e doesn't trade it) the difference is much bigger.