For lots of reasons both good and bad, Amex gets talked about quite a bit on these forums.
We often discuss their fees, compare the merits of their rewards and contras their services to other issuers on whose "best" for a certain need. Where they are far and away still without peer is when it comes to tax time. No one even comes close to their year end summary and the ability to upload corresponding receipts and mark notations on their business cards.
I was making my quarterly payments before filing an extension and this process is so convenient, organized and streamlined with Amex. All business charges and other tax deductible receipts easily organize, tagged, notated and with associating receipts uploaded under the charge. Chase is great, but their jot system and year end summary isn't nearly as comprehensive as Amex's.
Any business prosperous enough will eventually get audited. This process is a time saver and with all corresponding receipts marked accordingly (IRS rules require dining to list client names and itemized on the bill) and makes an audit go much smoother than having paper receipts scattered, missing or written in a ledger.
