The brief synopsis of the Pro features mentioned being able to bill clients using payment methods setup on either my account or on my clients account, or just being able to send the shopping cart to them directly to purchase.

Well, I can't seem to find out how to do anything except pay for the cart contents using the clients' payment method. But lets assume this works for a moment and I do in fact see my configured payment methods in addition to my client's.

Here's the problem: the payment method I can see only lists the card type - not the last 4 of the card. I understand the security risks in being able to see the last 4 of the card, so I'd like to recommend an alternative. Allow the ability to give payment methods nicknames.

This gives way to a much more convenient way to manage payments for clients. Lets say I setup a payment method in my account and give it a nickname of my company name and an internal phrase used to identify that particular card, while my client already has a payment method setup with no nicknname (or with one - it works either way). Now when I manage that client's purchases/renewals from Pro, I can see clearly which card is mine, and which one is the client's instead of just seeing "MasterCard" twice...

Here's another reason that payment method nicknames are better - my clients usually give me access to their accounts directly, so when they have a product renewal or new product that needs to be paid for, they usually tell me which card to use by mentioning the last 4 of the card in an email or over the phone. If the clients had nicknamed the card with something more descriptive than a 4 digit number, they would be able to reference that nickname instead of the actual last 4 of the card. This marginally improves security because 0% of the card/account details are transmitted from the client to me. And if the nickname trumps the card brand, then I wouldn't even know what number the cards starts with (Visa=4, MC=5, etc..).

I know this seems trivial, but I can see it being incredibly useful.

But this is in a perfect world - because as of now I can only see my client's payment methods and not mine, so lets get that fixed first :-)