Hunter change/update models..
.. very often , even compared to other major mass production brands. In the past -and still for some up-scale small companies- models were changed if and when they weren't selling well anymore.or a 'face lift' needed.These days is has more to do with marketing issues, other brands 'new releases', and less with their being succesfull and well designed -or not-..much like cars..On the negative side ,there is probably not that much effort and attention to details at design stage , since it is expected in advance that the production run will last few years only ,and whatever problems will be discovered can be dealt with in next model..Also , market price go down more when production ceased..