Lenovo (LNVGY 3.74%) recently announced the next laptop in its Yoga Pro line of convertible PCs: the Yoga 3 Pro. It packs Intel's (INTC 0.64%) Core M processor, which the chipmaker's CEO said offers "full Core performance in both compute and graphics in a fanless design." At a glance, it appears Intel has delivered what is essentially the perfect processor for a next-generation Apple (AAPL 1.27%) MacBook Air.

That is, until we dig a little bit deeper.

You'll never guess what reviewers disliked about the Yoga 3 Pro
I read an in-depth review of the Yoga 3 Pro by website Ultrabook Review, and a number of things stood out to me as downright puzzling. First off, it turns out the Yoga 3 Pro actually has a fan designed to cool the CPU. So much for fanless design.

Additionally, in PC Pro's review of the Yoga 3 Pro, the reviewer pointed out that in its "Real World Benchmarks" test suite, the Core M 5Y70 performed about 35% slower than the Core i5-4200U found in the last-generation Yoga 2 Pro. That's to be expected given that the power envelope is significantly lower. However, the following subjective impression from Ultrabook Review seems the most troubling issue:

This Yoga 3 Pro handles basic activities mostly fine, including light browsing, editing texts and some photos or watching 1080p video content. However, some programs work smoother on this platform than others. For instance, Chrome 38 is awful. Trying to watch Youtube clips or browsing in Chrome lead to an appalling experience, with everything lagging and choking. Internet Explorer on the other hand works far better. It can deal with 1080P and even 4K Youtube streams, as well as medium browsing with 6 to 10 tabs opened. And this is just one of the examples. The same can be said about playing videos with the VLC player (smooth), as opposed to playing them with MediaPlayer Classic (choppy).

While I am hesitant to speak on behalf of most mainstream computer buyers, I don't think a computer that costs over $1,300 should have trouble running Google (GOOG 0.74%) (GOOGL 0.55%) Chrome. It's doesn't seem that having "thin and light" will be worth giving up basic usability for most users.

There's little chance Apple will put this in a MacBook Air
While I think a fanless MacBook Air is fundamentally a good idea, I'm not convinced the current iteration of Core M is good enough to do it. Apple has shown a strong inclination to improve performance generation on generation, not to regress.

A good example of this is Apple's iPad Air 2. Apple made the device significantly thinner and lighter than the prior-generation model, but it did not regress on performance. In fact, it added substantially more graphics and processor performance. Engadget reported that the iPad Air 2's battery life is down a bit from the original iPad Air, but it also noted that Apple went with a lower-capacity battery (from 32.4 watt hours to 27.3 watt hours) in the iPad Air 2.

Apple is unlikely to put a Core M inside of its next MacBook Air should it lead to a noticeable performance regression even in common tasks such as watching YouTube videos and browsing the Web. 

I would be surprised if the next-generation MacBook Air included a Core M processor; I now expect full 15-watt Core i5 and i7 processors in future MacBook Air products. While Apple won't be able to claim that its next-generation MacBook Air is "fanless," I'm sure it will offer a very fast, vastly improved system housed in a best-in-class industrial design.