I just picked up a Sig SP2022 and the Adaptive Carbine Platform - Enhanced. Love the SP2022...great fit, nice trigger, easy action and awesome sights. The slide release is within easy thumb reach and easily manipulated. The magazine release is easy and the mag clears the gun without any issues.
The ACP....if you get one, be prepared to spend sometime with a Dremel tool and a file to get the lower rail adapter to fit on your gun. I spent about an hour on the polymer adapter to get it to fit on the gun rails and lock in with the key lock. Just take your time and remember that when you remove more material than you needed, you can't put it back.
The ACP is a quality accessory and depending on which variant you buy, can be pricey. The charging system is a bit clunky and the charging handle is a bit small for the leverage you need to cycle the handgun, but you're only going to need to charge the gun all the time. The firearm locking into the ACP positively and there is no slop in firearm fit. The system comes with an adapter for Glock's and Sig - but don't buy into the marketing that 'virtually every handgun' will fit.
The Sig red dot optic that comes in the enhanced variant is compact and has 12 settings for brightness control. Trying to find the right location on the rail for use is a matter of taste, eye sight and arm reach.