I think your reasoning is quite flawed, Marc. There are many, many reefers with huge systems in excess of 1000 gallons that run needlewheels. Many of these tanks are outstanding.
To make a blanket statement like "Needlewheels just can't cut it and keep up with large systems such as yours", without backing it up with facts is just ignorant. Most folks tend to defend their purchases (yours being Lifereef), however, be careful not to negate the many successful reefs using newer technology than the simple venturi. In fact, if you were to poll the membership here as to the best method of skimming, the needlewheel would probably be the hands down winner.
I've had a few Lifereef skimmers in the past and I really liked them, but I think their largest size skimmer (VS3-72) would be grossly insufficient for a volume of water greater than 500 gallons. Sure, it would work, but with a larger skimmer you would have better control and increased skimmate.