I, too am impressed with the HK45 & the smaller HK45compact in .45acp(LEM).
I'd be a bit leery of spending a lot of $$$ on a HK45 LEM after watching a brief T&E video on
www.youtube.com 
.
The Glock 21 & 30 model .45acp pistols seem to have a more robust/durable design but as a left-hander, I can see the merits of the HK45 pistols.
As posted, the HK LEM(law enforcement modification) has been in use for many years with DHS(Dept of Homeland Security) & the FFDO(Federal Flight Deck Officer) program(USP .40S&W LEM).
ClydeFrog