Hi a friend of mine runs a 660 or 850 mill at my place of work (a bigger version of your 450), we also have a Dugard lathe, both are less than a year old, the only issue I know of on the mill was when we wanted to use oversize/ large diameter tooling, We had a problem because the tools are put away into random pocket locations which ment it dropped a tool when it clashed with another large tool in the next pocket

as far as I know the service is 'O.K' I'll ask for you if you really need to know!!

Pat