That is awesome feedback!
I've used the TSSP4038 for continuous data transmission (bootloading over IR) but I wasn't aware it would work at 56kHz.
That's good to know, going to experiment with that.
The VS1838b parts from eBay have been great, but I haven't been pushing them over 32bits.
About 300 of them were in use for the firefly project ( http://www.lumipendant.com/
), where they would send a 32bit packet to set up a wearable social network.
Interestingly, in the firefly I 'detuned' the transmitters to reduce the transmission distance to about 3 meters.
First by reducing the duty cycle to the minimum (1 cycle on) and then by moving away from 38kHz.
Adjusting the transmit power allowed for range sensing but it wasn't implemented in the final build.
The LEDs used were PLCC2 package with 150 degree spread to get the most coverage and least distance.
I like the idea of using two different angles for the LEDs on the shield, probably I will rebag the kits to include that.