Unless you don't mind soldering and/or building a custom keyboard from scratch that's a huge selling point.
Source: I'm mechanical keyboard enthusiast :)
Do you have better ones?
(Positioning your hands by sight may not be that uncommon among people who learned to type before the F and J markers became commonplace on computers. I was in my late teens before I first encountered them, and I had to have their purpose explained to me.)
Just because it's a new solid board outside of the custom market doesn't make it a selling point.
I've used a MX Brown at work for 6 months (45g) and it was too soft. Nice feel but just too soft. I use a MX Black at home (60g) which I enjoy, and for the past 4 or so months, I've been using a MX Clear (55g) at work, and it's my favourite typing keyboard to date. The increased activation force (55g) and even higher bottoming-out force(65g) is why I bought it. I love this keyboard and it looks amazing too ;) http://mrinterface.com/sites/default/files/styles/mywatermar...
So, yeah, definitely not enough to make me replace a mechanical keyboard I already have, but perhaps enough to make me consider getting it over my current one (das) if I didn't already own one.