Records

Overall I find record types easier then CDT yet in few areas CDTs win. Right now I can think of Optimistic locking - Record Type needs extra considerations than CDTs.

Will come back if I recall more such cases. 

Yes, and no ... depends on your use case. There is no general answer to your question.

This question very commonly being asked record or cdt  but i would say it's based on use case.

Record Types focus on easy data presentation and UI integration with some overhead, while CDTs offer more flexible and detailed data modeling without built-in UI features; choose based on whether you need simplicity and UI support (Record Types) or control and backend data handling (CDTs).

Record Types have some disadvantages compared to CDTs, including limited flexibility as they can't be used in all places where CDTs work,  potential performance overhead for simple data operations, and more complex migration paths when converting existing CDT-based applications. They also require learning different design patterns and create tighter coupling to underlying data sources. Despite these limitations, Record Types generally offer superior benefits in data management, security features, and user experience that make them the preferred choice for modern Appian development.

There have been some reports of limitations in terms of performance at higher scale (150+ concurrent users).

It only supports a limited number of rows (although that number keeps growing).

Hi 

Please check the Overview section of the below documentation link:
Custom Data Types (CDTs) - Appian 25.2