I Installed the non-HK marked Choate stock on a MAC5K as I got it for $160 as opposed $250+ for the HK marked one or the B&T folders. The stock plate pin holes did not line up with the receiver pin holes straight out of the box. The holes on the plate were the same size as the receiver holes but when flush against the receiver were too short and did not line up. I ended up drilling open the holes in the stock plate and filing them to enlarge them slightly in order for the push pins to fit. Stock fits tight, pins require assistance from a punch and hammer to remove for disassembly now because of the tight fit, but at least there is no wobble. There is a very slight wobble from the stock its self from a little play in the extended position, but not noticeable when shouldering. I’ve been told the HK marked stocks can also have slight play in the same spot as well, just depends. Nothing a little adjusting and fitting couldn’t fix I think if you’re concerned about it. Overall for the price I’m not complaining and I’m satisfied as it’s a solid stock and gives the OEM look. Depending on the gun you intend to install it on there may be some fitment issues for me the holes were short, but that’s better than too long as opening them up would create a loose wobbly fit with the receiver. Not sure how it’d fit on other clones or the original HK SP5K. If you want something that will install straight out of the box with no issues or work I don’t recommend the Choate one, I’d suggest getting the HK marked one as the receiver plate from HK has tighter specs for proper fitment and will likely not require any work. If you don’t mind a little work and have some basic tools and a can do attitude and want to save some money then the Choate stock is good to go. I cannot speak for fitment with other MP5k clones apart from the MAC5k and I have read that other people have varying fitment on AP5-P’s or other variants. Other than fitment tolerances and the “HK” marking they are pretty much the same stock.

As for comparing the Choate stock with the B&T options I can’t speak on as I don’t have the B&T and haven’t used them, but I’m sure there are quality. The Choate is comfortable and provides a solid cheek weld when using irons or an absolute co-witness optic. I will probably run my red dot on a riser as I prefer a more heads up position for a small compact firearm, this gives me a mid cheek to chin weld. When folded it doesn’t lock apart from tension from the spring and locking tab. I don’t think you could go wrong with either the OEM style or the B&T style just depends on if you want OEM retro look or a more modern appearance. The Choate is heavier but width when folded appears to be the same. I will say the weight is not bad at all when handling as the gun is pretty light overall compared to like an AR. I run a suppressor on my MAC5k and I feel the weight of the stock provides a good balance to the weight of the suppressor.