Hydrates -- are they really icelike?

In following the story of the oil leak in the Gulf of Mexico, I read this Washington Post article. When it got to this one part, I started wondering:

Crews had been delayed after icelike crystals - called hydrates - formed on the blowout preventer. The device couldn't be safely hoisted from the water until the hydrates melted because the hydrates are combustible, said Darin Hilton, the captain of the Helix Q4000.

Hydrates form when gases such as methane mix with water under high pressure and cold temperatures. The crystals caused BP PLC problems in May, when hydrates formed on a 100-ton, four-story dome the company tried to place over the leak to contain it.

So, I started searching for information and photos of hydrates. I found this which is really informative about hydrates. Part of what is shared there written by John Osegovic:

Gas hydrates are often described as "a type of ice" or "ice-like". The chemistry of gas hydrates is very different from ice and the analogy, while widely used, is often unfortunate.

Gas hydrates are typically named for the guest. Methane hydrate has methane as the guest and water as the host. Guests are usually small molecules, but some larger molecules can be included in the structure. Hydrates can also contain more than one guest. These have various names including mixed-, compound-, and binary- hydrates. An example of a mixed gas hydrate is natural gas hydrate. Natural gas hydrate may contain methane, ethane, propane, butane, carbon dioxide, and hydrogen sulfide all trapped in different cages but in the same continuous water molecule network.