I own a Smith & Wesson M&P40C, the compact version of the full size M&P semi-auto pistol. This pistol is constructed soemwhat similar to the Sigma but it does have some differences that make it a slightly better pistol.
The guide rod is solid steel instead of plastic and the spring is a flat wound spring instead of a round wound spring, the flat wound is more expensive to produce and can be sturdier than the round wire spring.
The safety system is the same as for many semi-autos, a trigger safety that requires the proper placement of the trigger finger to de-activate the trigger safety. The trigger itself is rather substantial and will require some effort to pull back for smaller hands. This strong trigger pull is the main safety feature, you've got to m.ean it to pull it, even me with my monstrous hands.
These pistols are also available in 9mm, .40S&W and .45acp just like Glocks and Sigmas. Mine is chambered for .40S&W for a good reason. I like .40S&W and my Sigma is chambered for .40S&W and I reload .40S&W. Kind of have some continuity going there.
This pistol, while being a compact frame, is not sized appropriately for pocket carry but can be easily carried concealed in an IWB holster or a 4 position holster anywhere around the waist. I would carry mine in a belt slide holster at the small of my back once I obtain my CWP, still haven't been able to get it yet.
The magazines are sturdy and carry 10 double stacked rounds which makes for a substantial grip for large hands as well as moderate sized and smaller hands. With new purchase there is a flush magazine and an extended magazine included in the package but both are 10 rounds only. Additional magazines are available from many sources, in the $35USD or so range
Being compact and me with really big hands, I can only get two fingers around the grip. Even so, the recoil is quite manageable for me, not too much muzzle rise on discharge. Others will likely experience different amounts and ranges of recoil.
Care-taking is fairly simple and cleaning is very easy. No more difficult than many and similar is scope with the rest, except the M1911A1, that requires the removal of the barrel bushing. The M&P series do not have a bushing, it's an interference fit between the slide and the barrel.
The feed ramp into the barrel is smoothly polished straight from the manufacturer and does not require any touch up. The barrel has six grooves with a right hand twist but I don't know the turn rate, it's reasonable for a .40S&W.
This pistol is also quite accurate with whatever I have fed it and keeps fair groups at 35 yards where I shoot.
I do have one complaint, the sights are a bit dark for my eyes but I can fix that with the glo-paint I bought from a dealer. I'll be using it for the others that also have dark for me sights.
All in all, the Smith & Wesson M&P compact series of pistols is a good investment; good price, good firearm and a good manufacturer who stands behind their product.
An additional note, there was a small issue with the magazine release button, it wore out very quickly. I called Smith & Wesson and told them my problem and they shipped me a replacement right away and, included a few extra for those "just in case" moments. Funny thing is, the replacement button has yet to wear appreciably.
If you're in the market for a good pistol, check out the M&P series. I like mine, you'll surely like yours.