I don't know how that other one works but it is likely to be a loop aerial boosted to the hilt to make it useable. But a booster is analogous to a volume control and is only as good as its input. All aerials are loop aerials with varying degrees of channeling the signal onto the loop. The Telecam is a perfectly good aerial and because it doesn't come with a booster you can select your own.
http://en.wikipedia.org/wiki/Decibel click there for an explanation of what dB is.