My Ciener one works better with the 32 lb mainspring than a 26lb one.
Also, I was running into issues with the kit not firing the gun. I tried [what I thought was] everything.
I now think that the rod that moves up from the trigger [trigger lever? Lifter?] to push up on the front of the sear bar [causing back to push on the sear] was a bit too wide and was sitting partially on the center rail of the Ceiner slide and partially on the sear bar.
I only came to this conclusion when I got a BHP .40 and put the kit on it. The kit worked more reliably there. I got to thinking and realized that the .40 trigger lever was about 1/2 as wide at the upper tip: maybe that was causing the interference on my 9mm framed BHP?
The Argentinian one is a MACS conversion kit.
I had it and got a used Ceiner kit to replace it with.
The MACS has a habit of allowing the sear pivot pin to bounce to the left, which prevents the slide from moving properly and makes take-down difficult.
The MACS has a threaded barrel for a tensioning nut that also adjusts the way it sits on the frame. I like this design, but live in California, where a threaded barrel on a semi-auto handgun is technically illegal.
The MACS kit I had didn't feed as reliably as the Ceiner, but it fired more reliably.
The Ceiner began to fire as reliably when I fixed the deformed firing pin [who would have thought a firing pin mushrooming might make inconsistent firing].
Ceiner is a pain to work with, but spare parts and magazines are accessible. If you are in a non-regulated to heck state, you can get higher capacity magazines too [14 rounds?], while California and others can only get 10 rounders.
If you are buying Ceiner, get the Ceiner with the adjustable sights. I want to replace my rear one with an adjustable, but haven't gotten around to it.
If you are buying Ceiner, it will be a trip down memory row to the days where you saw something for sale in a magazine. You mailed in your check/Money Order with the coupon from the magazine and a description of what you wanted. The parts arrived 2-6 weeks later. There was no contact in between. That is what working with Ceiner is like.
I ordered over $120 in parts from him, sent a check, and the parts arrived 3 weeks after the check cleared my bank: which matches his listed shipping/sales policies.
Whatever you do: enjoy.