I have an genuine ELM327 $canner which is rs232 and two bluetooth ones from C. H. Ina.
. They all have been flawless. I bought the second BT scanner because the first one was borrowed, extended loan it would seem.
The power is in the SW. The OBD SW that came with the original was great, but no frills. Torque is a lot more fun and very handy since I can now use my phone as a diag tool. I also recently loaded Diag My Toyota. Again no frills but it seems to access more than the basic engine codes. I can see other sensors such as shifter position etc... So it has it's place too.