Yes, Diablo WiFi 2.3 has overheating problems. But 2.4 is cooler. You can cool down the modules by screwing down the WiFi power to ~1 and switching off the status LED's at the Diablo itself and bringing the WiFi router close to TV.
Anyway, with 2.3 and 2.4 ( and Samsung UE55C6700 ) I have a lot of stability problems with WiFi on SD channels, but with HD channel its running much better, but not 100% stable. I guess the common interface on Samsung TV is doing some troubles. But I have found a lot of forum threads from other peoples where this module is running 100% stable on C-Series. If I will put this Diablo WiFi module into another TV from (other brand), then it's running 100% stable, too.
OSCAM is just a protocol router. OSCAM does not make sense on TV. To make the Samsung bright you need a softcam like CCCam. But you can connect with CCCam client to OSCAM server.
But be aware of this that in some countries it's not allowed to share one card to more then one TV. In my country it's allowed, by luck, but I'm forced to use the card inside the Diablo WiFi directly because of the WiFi stability problems above. I have switched off the WiFi functionality on my module.