I just bought one of these scopes & i have to say i think the optics are very good, i went for the Mamba after looking through my brothers Viper (don't like the turrets on the Viper though ) & i'm not dissapointed at parting with £180 i tell you!!
The only thing i have concern about is the 'removable' part on it as it looks a little loose on my scope & doesn't quite sit flush so looks a little cheap IMO, apart from that wicked bit of kit, used it down the local range last night & hope to test it later tonight on a lamping session.

Steve