Yep, as I mentioned earlier, most mainstream engines will deliver satisfactory performance, with minimal differences, discernible only by some sort of metering, or by a very professional flier.

If you read through a lot of the posts in this (and similar) threads you'll see that reports are almost always incredibly subjective. It's usually either "I own brand A and I love it. I've never owned brand B but I've heard bad things and I don't like it." or "I've owned brands A and B. Brand A's great, but I'm one person who had some problems that I couldn't fix with brand B so I don't like it."

To get a real feeling for good or bad engines you'd want to hear a fairly constant stream of people coming up with more or less the same problem from a given brand & model, and that simply doesn't happen. For example there's many people who dislike Super Tigres (usually because they're fiddly to tune) and at least as many people who rave about them (usually because they're powerful and inexpensive when tuned correctly). The trick when reading these reviews is telling the difference between a poor engine, and an incompetent user (no offense intended toward anyone reading this who may have had problems with any given engine in the past).