Call Park and SWCA each have their own characteristics:
[ul]
[li]Call Park can't park calls on buttons.[/li]
[li]Call Park don't take any button on a set.[/li]
[li]Call Park has one feature code.[/li]
[li]Call Park is limited to 25 calls.[/li]
[li]Call Park is system-wide.[/li]
[/ul]
[ul]
[li]SWCA can park calls on buttons.[/li]
[li]SWCA can take many buttons on a set.[/li]
[li]SWCA has many feature codes.[/li]
[li]SWCA is limited to 16 calls.[/li]
[li]SWCA can be divided into groups.[/li]
[/ul]
One feature might work better in some cases while the other might work better in other cases.
If a receptionist answers incoming calls for an entire business and parks them all, Call Park might work better. It will allow more calls to be parked simultaneously. It will also prevent the sets of the employees from being cluttered with a bunch of SWCA keys, especially if they handle only one call at a time.
If a receptionist answers incoming calls for two different departments and parks some of them, SWCA might work better. It will allow employees in one department to have their own SWCA keys (for example, 1 to 4) and employees in the other department to also have their own SWCA keys (for example, 5 to 8).
If your customer needs to park one call at a time, I'd go with Call Park. There is only one feature code to remember and the call will always be parked on 125 (or 109). If your customer needs to park many calls at once, you'll have to see if SWCA works from an ATA.