Let's get something out of the way:
Path of Mettle is actually awesome! Path of Mettle is almost effortless to play

When Path of Mettle enters the battlefield, it triggers a Simoon-like effect, dealing a point of damage to every creature that lacks first strike, double strike, vigilance, and / or haste.

The solution is simple: Just play creatures with one or more of these abilities, and the "Simoon" trigger will be one-sided; largely a Simoon for the same amount of mana.

We can consider the deck played by US National Champion Craig Krempels to the Top 8 of last week's Team Open as a model for this strategy, but many Red Deck creature shells can suffice.

All of Bomat Courier, Earthshaker Khenra, Ahn-Crop Crasher, Hazoret the Fervent, and Glorybringer (you know, just the creatures the old Ramunap Ruins deck played) start out with haste. This makes the first line on today's enchantment "free".

But flipping it is nearly free, also!

So long as you are playing such creatures, turning your Legendary Enchantment into a Legendary Land shouldn't be too tough.

When you flip Path of Mettle, you're doing it. You're really DOING IT

When the Path becomes Metzali, Tower of Triumph, "Triumph" may be closer than it initially seems. This land is super disruptive to many different kinds of opponents.

The "red" ability largely serves as a stand-in for the now-banned Ramunap Ruins.

The "white" ability has a broad range of applications, including (but not limited to) cutting of the ability for many control decks to win. Attacking with one creature? How about "randomly" putting that creature into the graveyard? The "white" ability can also ignore hexproof, so it is potentially a problem for the Hydras out of Energy variants.

Okay, sold! Um... So what's the gamble around Path of Mettle?

Why? The mana base of course!

Craig played a couple of Plains in his twenty-two land aggro deck. It was vital for him to play enough red (especially untapped) to be able to field some sixteen one drop creatures.

Will WotC print another Boros dual land? Will they just reprint one we already love?