Even for gliders in the local pattern you should certainly consider buying a FLARM.
In our club we decided to install it in every aircraft, even the paraclub decided to install devices in their drop planes.

We had serveral very very close calls:
- The Cessna Grand caravan in short final aborted the approach because of the flarm beeping like crazy.
Our twin was just below in front of him in his blind spot. Luckily he didn't wait a blink of an eye longer.
- A tow pilot with glider on the rope not seeing another glider in the pattern, the instructor too busy with the student.
Only the flarm alerted them to make evasive manoevres.
- And a few others...

Flarm certainly saved our asses several times


Bert