Please look at some Diamondback related information. I know of 2 people who both have owned and disposed of their Diamondbacks with in 3 months. I have read little positive about them, however I can not say I have any first hand experiance with one. I know also I never will because of the exposure I have had. As a general rule of thumb I never buy a gun manufactured in Florida.
The LC9 is a nice little gun and I can carry one in my front pocket. With a good holster it is protected and appears to be a wallet or some such object. My advice, which is only one mans opinion is shy away from the DB get the Ruger. You may hear advice to the contrary, you may be luckier then my 2 friends. I don't know. I am just offering my opinion and hope it is appreciated in your decision making process.