Worst Market Depth and Slippage

I think their market depth is worst than any other broker I've tried before, especially for indices. One of the most recent examples is when I'm trying to trade US30 and I realized that the price regularly fills 2 whole points higher than the quoted price. Their depth of market shows they only have single-digit lots at the quoted price. Although it's true that they are consistently keeping tight spreads for a smaller lot, if you are trading over 10 lots, it will feel more pricey. The slippages are also really bad in my opinion, most brokers easily fill 100 lots around quoted price with less slippage. Slippage for large lots is normal but 2 whole points slippage is unheard of for 100 lots in normal trading non-news times.