Unfortunately, I recently had a similar experience with Citi. I received numerous pre-approved invitation letters from them and decided to apply for the Citi Custom Cash card. However, I found the application process to be quite challenging compared to my experiences with other banks. Despite having more than 10 cards from reputable institutions such as BoFA, Chase, Capital One, Amex, and Discover, I encountered several hurdles.

After submitting my online application, I received a letter from Citi about a week later, requesting additional documents to be sent via mail. This unexpected request prompted me to reconsider my decision and ultimately led me to withdraw my application.

Here are a few points I believe Citi could improve upon:

1. The pre-approved offer letter from Citi initially attracted me, but their inability to make a decision based on the information provided during the online application was disappointing. In contrast, when I applied with other banks, I received approval notices and physical cards within about a week.
   
2. Citi should consider enhancing their online application form to include all the necessary information required for them to make an informed decision. This would not only streamline the process but also prevent delays caused by additional document requests.
   
3. It's essential for the application process to be straightforward and smooth to ensure customer satisfaction. Clear communication and efficient procedures are crucial in establishing trust and maintaining a positive banking experience.