COALESCE or CASE more efficient and/or standard

Question

In terms of x compared to y.

• Does x comply with sql standards better? [apologies if subjective]
• Is x more efficient than y?
• Or are these

Answer 1

In this case I would use COALESCE ( which provides more levels than ISNULL) rather than the CASE stement.

The CASE statement seems a bit bulky here, seeing as you are only checking for NULLs anyway.