I tried HDM 14 in a Dell Windows 8.1 laptop, working from a WinPE 5.0. The operation is very slow. It isn´t slow to create images, but when navigating the interfaces, and specially when a function is launched from the modern UI. I created the WinPE ISO with Boot Media Builder and WADK for Windows 8.1, then "burned" the USB keys with Rufus. When I use the same WinPE in an older computer (that has Windows 7 installed), HDM 14 works much faster. Strange. This WINPE 5.0 (based on 8.1) with HDM 14, is slow in a recent computer that works well with 8.1, and fast in an older one which uses 7.