If the LeMeridien is half the price, that might make a difference, but keep in mind that as a Gold at the Hilton you will receive the buffet breakfast (for at least two guests, we received it for all four), as well as internet access, and have a good chance of an upgrade to the executive floor with lounge access. Even without the upgrade, you're still saving €15+ for internet, and €25+ for breakfast, so make sure to factor that in as well.

Both are good hotels...the base rooms at the Hilton still have a view of the Marina, while the classic rooms at the LeMeridien don't have a view of anything, if that's a factor.