I can't give experience on auto...but after saying a zillion times I would NOT take a hit for the CLI, I bit the bullet yesterday and asked for one. While I had the reps on the phone (spoke to 2 of them) I asked both of them if there was any rhyme or reason to their auto CLI's and they said it was all computer generated. I asked specifically if there was any set time when they review the accounts, say at 6 months or 1 year and they said nope...just randomly computer generated.
My limit was 1k I was putting between 1500-2000 through it a month and PIF 4-5 times per month in big payments. It was getting ridiculous and I was getting annoyed with PIF and wait for payment to clear so I could use the card again, etc. So, I called and told them so. Computer CLI me for $300...told them it was a joke and asked for a supervisor. Supervisor came on the phone, told me to hold on and said the "best he could do at this time was raise my limit to $3K." They also told me to try again once my account has 6 months of history, but I'm not wasting another inquiry on them in 3 more months.
So....if you already have a solid 6 months of history, and you have been pushing over 2x your limit through each month...and you don't mind the inquiry. I'd call them. If you tell them like I did, that you want to use the card more, but you get stuck for several days at a time waiting for payments to post and it's becoming more of an inconvenience to use the card, then a benefit, they will probably up you.