The majority of my 30 rd aluminum mags are D&H that I bought several at a time when I order parts from Bravo Company, DSG Arms, LaRue Tactical, CDNN Sports, etc, around over 50 mags total, about half are gray and half are black finish color.
I prefer D&H more durable and slippery Teflon finish rather than the usual dry lube mil-spec finish, which I still have my oldest Colt I bought in the late 1970s almost no finish remaining.
All my D&H mags I upgraded every one with Magpul gen 3 anti-tilt followers, these followers also have Teflon and combined with the Teflon finish of the mag body reduces friction so no lube are required (just my own opinion), on my most used mag I also upgraded them with Wolff extra power springs which I mainly use with my carbine gas system carbines, the carbine gas cycling is fast so the extra power spring could keep up with the faster bolt speed.
On some of my most used mags I also use Magpul Ranger plates with mag pull loops with mags that I use with my chest rig (6 to 12 mags carrier).
The minimum rounds that I test my mags before trusting them for defense use are from 90 to 100 rounds without FTF, but I feel better if I fired at least 300 rounds (10 full mag loads).
I don't have any D&H mags with high round count because I'm just using them as spare back up, but I've been using them since 2005, I'm mainly using polymer mags such as PMAG, Lancer Systems, and others.
FYI, D&H mags are also used by the Canadian army and Israeli Defense Forces according to past discussion threads here at ARFCOM.
I'll still keep on buying D&H when they're on sale as much as I could afford, I would recommend everyone to stack them deep now because you never know when high capacity mags are going to be banned again in the future.