XC Mountain Bike Sizing - The Important Measurements

I looked through past threads and didn’t see anything that touched on this. I want to know what the crucial measurements are for xc mountain bikes.

I am looking at going from a Kona Honzo (Trail) to an XC bike. I found a nice used Specialized Epic, however, its a size larger (XL) than my Honzo. I am looking at the geometry charts for both bikes and I’m not sure which measurements are the most important with mountain bikes. I am 6’1" (~185 cm) and typically ride a Giant M/L frame on the road/CX. In some other research I did I see people saying stack and reach are the most important on MTB.

Here’s a comparison of the bikes geometry (L Honzo, XL Epic)

  1. Stack 642, 636
  2. Reach 475, 480
  3. Top Tube 647, 662
  4. Seat Tube 470, 520
  5. Standover 750, 847
  6. Front Center 769, 753

Taking into account these are different styles of bikes, do you think these compare well? Are there other measurements I want to look at? I don’t want to waste my time driving 1.5 hours both ways to find out it doesn’t come to to fitting.