There's not a hard answer to this question, it comes down to personal preference.

For many years the answer was size down. The thought being smaller frames are lighter, shorter tubes make a stiffer structure, smaller bikes are more playful. And there's something to this line of reasoning.

But there's another camp and personally I'm in it (I'm just an inch taller than you and I ride an XL frame). Longer wheelbase bikes can be more stable at speed, more forgiving of wonky take-offs and landings and some of us simply like a bike that feels roomy.

Demo some bikes of different sizes if you can.
=sParty

 

Not only height. Some at your height have longer legs and a shorter torso and arms. They can fit better on a L. And vise versa.
Actual inseam tells something about that. not pants size. Measure yours.
Plus all large bikes aren't the same. Look to the geo and check the reach number. Differences between lots of bikes. Newer geo is moving toward longer reach and slacker head tube angles. Ride some bikes and take note of the reach differences. Demos on trails are better than test rides. But on a test ride go into ditches and on the grass for a little more info.

The Pitch has only 440mm reach on a large. It's unlikely you'll fit on that.

Bikes like the Pitch have forks without rebound damping adjustment. They pogo hitting multiple rocks. The Pitch says they've solved that. They have plastic bushings inside instead of metal. Won't last long on trails. They're designed for bike paths and smooth trails. Just a spring on one side in there.

This is a bike that's recommended.
Scout 290 Sport 2019 | Nukeproof
https://www.chainreactioncycles.com/us/en/nukeproof-scout-290-sport-mountain-bike-2019/rp-prod170308

 

Thanks Sparticus and eb1888 for your replies, I super appreciate it.

I'm tempted to try the XL version since you guys have made great points.

I'll give my impressions after ive had time to try the bike this week and possibly may have other questions concerning size.

 

If you visit a Specialized dealer, they will fit you to the correct bike size. I'm 5'11" and I ride a Large in Specialized bikes but I'm a medium on some Giant bikes.

 

I'm the exact same height as you, and have run into the same problem a number of times. I'm often in between sizes, or right at the edge.

I currently ride a size large, 2018 Kona Process 153. It has a 475mm of reach (distance from pedals to top of fork), if that helps give you a ballpark idea of what someone your same size is using. For me the size feels perfect, but I was lucky enough to get to sit on one before I bought it.

Vitus has some good deals on hardtails (sentier, nucleus) as well, as does Ragley (big Al), in addition to the nukeproof scout linked above. They may be worth looking at to see what suits your fancy.