They solve different parts of the same problem, and they're often used together.
An exchange fund lets you diversify immediately, without triggering tax, but requires a seven-year holding period. Cache Long/Short may complement that by helping you manage remaining positions more flexibly, seeking to generate tax losses to offset gains as you gradually sell shares, handle fund distributions, or plan for future liquidity events.
You can use both: an exchange fund for the portion you're comfortable locking up, and Cache Long/Short for the portion you want to work down over time.