I went into my local gun store about 3 months ago eyes wide open. Met a really helpful guy at the store that took me to EVERY case and educated me about each pistol. Really top notch customer service. I held just about every pistol in the store.
I landed on the S&W M&P40c (compact). After 600 rounds, I would say it has the reliability of the Glock with way more sex appeal. No malfunctions, and I have fed that gun every cheap box of ammo made. It will gobble up and fire anything, I might try some pebble and rocks the next time I'm at the range to see how it does.
The Glock: For me, the Glock is just about as reliable as anyone can expect a handgun to be. Hands down, that is some fantastic engineering... But it's ugly. I mean really, really ugly. The word that comes to mind is 'utility'. It looks like a mass produced cordless drill. It's boxy and black and that's about it. Plus it feels awful in my hand. I feel like I'm holding something in my hand. You should not feel like you're holding 'something' when holding a weapon. It should feel like an extension of your apendage.
Go to the store and just hold that M&P40c. You can read countless reviews about how this handgun feels. After holding it myself I can tell you it feels good. It fits. And if it doesn't try one of the other 2 backstraps. If it still doesn't fit, you've got weird hands, find a different weapon!
I too was worried about the recoil. If find that the snappy recoil of a typical .40 is not present with the M&Pc. It's way closer to the nice push of the .45.
My advice about calibers would be to go read Wikipedia's description of how and why the .40 caliber was developed. Look at the ballistics gel and judge for yourself. If you're not convinced, it comes in both 9mm and .45 as well!
Get it with a thumb safety, even if you have to order it and wait. The words 'trigger' and 'saftey' do not belong in the same sentence. (I just put them together in that last sentence for dramatic effect!)
...and finally YES. This handgun is very easy to conceal.
Good luck!