It sounds like ScanTool pulled a fast one -- deciding to discontinue the ElmScan 5, selling it cheap on Amazon ($30) to get rid of excess stock, and only then announcing that it is being discontinued. I had assumed that $30 was their normal discounted price on Amazon, but it now appears in their "discontinued" section. If anyone is looking to buy one, now is the time to do so while it is showing as available on Amazon.
Originally Posted by ChrisC
The main drawback I found to the Elmscan 5 is that it was limited to a 500kbps connection to the computer, which caused data to sometimes get lost. In most cases, it isn't a big deal (as much of the data is transmitted often enough that losing some isn't a problem). But you never know if something useful might get lost. I'm not sure of the OBDLink SX offers a faster connection; their site doesn't mention it. Their claim of a large buffer should get around the problem even at 500kbps, though (the Elmscan 5 has a 256 byte buffer).
Something else to be aware of is that there are some cheap no-name OBD2 readers out there that use counterfeit ELM chips. And some may not support speeds high enough to be worthwhile (if you're thinking of using the "monitor all" mode, 500kbps should be the minimum considered; the ElmScan 5 and presumably the OBDLink SX do 500kbps).
Personal Best Charge: 57.2 miles
Best Day: 71.3 miles, no gas (49.9 on full charge, 21.4 on ~4 hours @120V)
Over 4 billion pieces of data collected on the Volt OBD2 port