As of today, my collection of Malkoff lights/dropins is officially "sufficient".
I've got the neutral MDC AA. This is my primarily my backup light since it clips so nicely into my front pocket. It's also my travel light since I can use common batteries and not worry about keeping a charger. My only complaint is the PWM. I notice it, but I can live with it.
I've got the M61 219B in my MD2. I should have gotten the M61L 219B instead, but this is fine. This is my workhorse light. 2 modes and plenty of run time for my meager needs.
I've got the M61 is my 6P. This is the module that came in my MD2, but I like it here better.
I've got the M31LL in a VME head on a Lumens Factory e1 body. I got the M31LL as an anniversary gift from my wife (she asked me what I wanted...) and it was fun to feed it various batteries until I realized how much current it pulled from 1.2v. Now I'm feeding it 3v. I've never purchased a CR123A in my life, but I have a dozen or so that came with lights. I'll eventually have do decide if I want to keep feeding it CR123A or invest in a 2AA body for it...but that's years away at this rate.
My M61WLL is in a Nextorch plastic host which is a convenient beater for around the house. It is strangely satisfying in the hand.
And today I received the M61LLL 219B for my Lumens Factory e2 body. Identical beam and output as the M31LL, but I can run it forever on a 16650 cell. I expect this to be a another work horse light for me like the MD2. I find it more comfortable in hand than both the MD2 and the LF e1 with VME.
I now have a module in every host I want to have ready, hence my collection is "sufficient". However, when the opportunity presents itself (typically when my wife buys a new pair of shoes or a purse), I will probably pick up a M61NL or M61NLL and a Surefire G2. Despite having 3 of the 219B modules, the Malkoff neutral is my favorite, but it's close.
Edit: spelling
--flatline