Success with Clone Scantool
I bought one of the generic scantools ("cheap clone" as I read in the post). It has worked perfectly and been very reliable. All of the ELM devices use the ELM327 (or earlier version) chip all come from the same source, so the quality is in the chip. Possibly there are some cheaply manufactured devices that are based on this chip, but it is the exception, most of them are good quality. Before I bought I checked the return policy.
Many of the complaints about these clones are not due to the device itself, but with incompatibility with software that is used. I tried a dozen programs and only found a few that worked with the generic device. The software builders can put in the design a probe that will only allow certain hardware to be used with the program. The ELM327 chip accommodates such tagging, and can be programmed with a free form "Manufacture Code" (another good feature of the chip). Software integrators can use this feature to lock out devices without the code.
For my purpose, I needed features found in different software packages, and I didn't want to spend $100+ each for each package. I wasted so much time trying to find the right software with no success, so I just wrote my own OBD2 program with excel, and VBA. It has been working perfectly with my "cheap clone" for some time now. It works seamlessly on SAE, ISO, CAN and other vehicle protocols (about 10 total). I see this is an old post, but I hope it helps anyways.