I got involved with legacy FourSevens in November 2007 when I bought a Fenix L0D AAA (still have it). That led to the L1D P2D combo with the CR123A/AA tubes. Over the years, especially after FourSevens separated from Fenix and sold FourSevens lights exclusively, I bought almost one of everything. But not so much in recent years, mainly because:
-The demise of Neutral. I can see Warms disappearing, but Neutral? Especially at the time when Cool Whites were really blue-ish/green-ish. Moved on to Zebralight, oLight, and Nitecore for neutrals.
-Two broken 360 headlamp adapters. The most brittle. plastic. ever.
-Weird designs like the Bolt and Bolt Mini, and Paladin.
-And the last straw for me was no Android interface for the Smart Lights. WTF? Well not specifically that it never materialized, but how David was so defensive of the lack of Android, including quoting his iOS developer who told him that Bluetooth for Android was almost impossible to program for. Really? Of course your iOS developer is going to say that--find a developer that can do both, or find a real Android developer! Ah, water under the bridge...
In the end I still use FourSevens lights every day (I use an 2xAA Quark as nightlight for my son, I just pulled my Titanium AA out of the drawer for fun, and I recently revisited the Atom A0 in stainless and titanium). David produced many great lights over the years, but probably what I will remember most is their fantastic customer service. I wish David all the best.