I have had 3 1HP machines over the years , and think they are all limited at best . CFM claims are unreliable . If the Dust Right has a bigger impeller , it will move more air . My Rikon has a 9" impeller , and it was the weakest of the 3 I have owned . Have a look at Grizzly also . 650 CFM at the end of a 4" flex line is a reach . If you find one w/ 10" - 11" impeller , you'll get much better results . I'd advise larger DC , even if you had to wait a while . If you expect to be in the hobby long , a 1HP machine will soon be " too small ".