ratio

Totally agree. I'd argue that a 27.5 "trail" bike and a 29er "trail" bike are really just different categories of bike. I've owned both, and they hit the same trail with a completely different feel. I see the merits of 29er wheels, especially for racing or for big frames. For a mid-travel bike, out in the woods riding around for S's and G's, I'm not so sure. If I could only own one FS trail bike it's definitely going to be a 27.5.

@withdignityifnotalacrity: I've been kind of thinking this, too. There are brands that will make you a steel single-speed, or a dedicated mullet bike, or a 29er back when they weren't popular. There really ought to be a brand for not forcing everybody onto gigantic wheels. Really though the best way would be wheel sizes matched to frame sizes. The video says Spesh are varying frame stiffness with size to make the different frames ride similarly. Why are they then going on to give every size frame the same XL wheels? Imagine a scenario where 10 years ago all cars, Geo Metro through F-350 ran on tiny Geo Metro wheels. And now all cars, Geo Metro through F-350 run on huge F-350 wheels. That wouldn't make any sense, but it's what happened with mountain bikes. I know there are a lot of people who think this is an improvement, but my intuition tells me most of them are above average height.