Is anyone familiar with the BFSIII HK-C1 – Binary Trigger Group – Ambi 3 Position Housing – HK SP5 & SP5K Spec :

https://hkparts.net/product/bfsiii-hk-c1-binary-trigger-group-ambi-3-position-housing-hk-sp5-spec.htm

Is this literally just a “plug-and-play” replacement for the standard HK SP5 trigger housing?
Is this binary trigger 100% reliable?
Is this available anywhere other than HKparts?

It is PnP for the SP5 or SP5K depending on which model you choose. Their price is was a little pricey when you could the triggers at a deal but not so much anymore. You may have to adjust the binary trigger adjustment screw to get it to function properly but there are instructions on how to do so. I have one in my SP5, it has functioned flawlessly. Timing of trigger pull is key in getting that FA simulation. Too bad ammo isn't $200 a case any more....lol

Thank you for taking the time to answer my questions. Very much appreciated!

I’ve never had or used a binary trigger. What does the “binary trigger adjustment screw” adjust? Is it a cycling rate issue? I’m not sure what you mean about timing the trigger pull; I’m not looking for full auto simulation so much as maybe quick double-taps and the occasional dump a bunch of lead on target .... errr... uhm.... OK,  maybe that is simulating full auto somewhat. LOL

Seriously, without having any binary trigger experience I have no idea what to expect. Not sure how concerned I should be about adjustment issues if yours has been flawless.

It’s been a while since I’ve had mine open but if I recall correctly, the screw is in the front of the trigger pack. Once installed on your receiver that screw “may” need to be adjusted up or down to get that fire on pull and release action. It’s not hard to do.  

It is a fantastic trigger. I’m not a big fan of the selector lever design, and wish it felt more like an HK selector. But the trigger itself works perfectly. Doubles are incredibly easy, and I can pull off four round and six round strings on target without difficulty.

Just get it. I ponied up for the hkparts pack and it's worked out great. Don't chase speed of shooting, just pull and release evenly and the full auto like shooting happens. Even works one handed.

Does anyone make replacement selector levers for the BFSIII that look more like stock levers?  I just hate the weird appearance of the lever and honestly is the only thing that keeps me from buying it.

If someone tells me the BFS trigger feels better than stock, that might make it a little bit more palatable, but that selector lever, though.

The trigger feels fine compared to stock, no complaints there. Check out custom smith manufacturing for some after market selector  levers. They look nicer than the bfs iii ones, but still don't feel as nice as real hk ones.

Why are you babying it? Slap that motherfucker like it owes you money