From what has been said on here in the past they're not the best of machines but are perfectly good for light duty work, the 181 is supposed to be a better machine as it uses better quality components. Butters are a superb company to deal with, I had problems with mine (caused by me working it too hard ) and they were very helpful in getting me back up and running.
TBH, I think if the choice was clarke or butters, similar spec for similar money, I'd probably choose butters