I have a S&W M&P Shield (.40) and freakin love the thing! The .40 holds 7+1 and 6+1 depending on the mag. With the 9mm you gain one more round. The Shield is less than 1-inch thick so it is extremely easy to conceal. The Shield is also rated to +P+ in case that matters to you. Shoots great and is very accurate for being a shorter barrelled pistol. Easy to clean and breakdown.
The Shield and Compact are comparable, but the Compact is still a dual stack mag format so it is considerably thicker but obviously holds many more rounds.