We have gotten a bit spoiled. I can still remember the frustration of only seeing 3 cell LED lights, and it seemed that most were long enough to use as a baseball bat. Pocket carry was out of the question. It was CMG that introduced us to the one cell LED light and one you could EDC. Had they been the first to introduce a AAA version of their Infinity, sans the battery saving feature that kept it a bit too dim, we would have welcomed it with open arms to the same extent that we welcomed the Infinity. However, Arc provides an exceptionlly engineered and quality constructed AAA. I don't personally think the Sonic matches the quality standard of the Arc AAA, but the quality is very reasonable for a mass produced light.
I give the Sonic a thumbs up. I've got a couple of them, and don't regret buying them at all. It won't be replacing my Arc, though.