I once owned 2 in .44 magnum. I sold the parkerized one and kept the chromed one.
Yes, they are very impractical, but are finely built and fitted. Nothing draws a crowd at the range like turning loose a magazine full with a D.E.
As noted, velocity is reduced to around 1250 fps. with 240 gr. bullets. I've chronograph compared my handloads fired from a 6" revolver, and the D.E. loses about 150 fps.