If you click "Apply Conditionals" the crit chance is wrong. It's assuming a maxed combo counter along with Gladiator Might's set bonus.
The actual crit chance is: 32 * (1 + (2.2 * 2) + .1) = 176%

Nerd Shit

Ignoring Armor

First heavy attack does approximately (assuming no statuses, orange crit, and ignoring armor):
[20, 140, 40] * (1 + 1.65 + 1.2) * (1 + 0.55) * 2 * (5.9 * 2) * (1 + 6) = [ 19 716, 138 016, 39 433 ]
Impact: 19,716
Puncture: 138,016
Slash: 39,433
Total: 197,165

Slash proc damage would do approximately (same assumptions):
0.35 * 197165 * (1 + 0.55) * (5.9 * 2) = 1 262 159
1,262,159 True Damage per Second for 5 seconds.

Second heavy attacks do approximately (assuming no statuses, orange crit, and ignoring armor):
[20, 140, 40] * (1 + 1.65 + 1.2) * (1 + 0.55) * 2 * (5.9 * 2) * (1 + 3) = [ 11 266 78 866, 22 533 ]
Impact: 11,266
Puncture: 78,866
Slash: 22,533
Total: 112,665

Slash proc damage would do approximately (same assumptions):
0.35 * 112665 * (1 + 0.55) * (5.9 * 2) = 904 595
904,595 True Damage per Second for 5 seconds.

With Armor

Now, let's say we're going up against a non steel path level 100 Heavy Gunner which has 6,441.15 Ferrite Armor.
This means we'll have to make some changes to the numbers we got above to accommodate for the armor and health types.

The damage calculation formula can be found here: https://warframe.fandom.com/wiki/Damage#Armored_Enemies

Considering those, the first heavy attack would do approximately (assuming no statuses and orange crit):
Impact:
19716 * ((300 / (300 + 6441.15)) * (1 - 0.25)) = 658
Puncture:
138016 * ((300 / (300 + 6441.15 * (1 - 0.5))) * (1 + 0.5)) = 17 641
Slash:
39443 * ((300 / (300 + 6441.15 * (1 + 0.15))) * (1 - 0.15) * (1 + 0.25)) = 1 631

Impact: 658
Puncture: 17,641
Slash: 1,631
Total: 19,930

With the slash procs doing approximately (same assumptions):
0.35 * 19930 * (1 + 0.55) * (5.9 * 2) = 127 581
127,581 True Damage per Second for 5 seconds.

The second heavy attacks would do approximately (assuming no statuses and orange crit):
Impact:
11266 * ((300 / (300 + 6441.15)) * (1 - 0.25)) = 376
Puncture:
78866 * ((300 / (300 + 6441.15 * (1 - 0.5))) * (1 + 0.5)) = 10 080
Slash:
22533 * ((300 / (300 + 6441.15 * (1 + 0.15))) * (1 - 0.15) * (1 + 0.25)) = 931

Impact: 376
Puncture: 10,080
Slash: 931
Total: 11,387

With the slash procs doing approximately (same assumptions):
0.35 * 11387 * (1 + 0.55) * (5.9 * 2) = 72 893
72,893 True Damage per Second for 5 seconds.

Let's replace that Heavy Gunner with a non steel path level 100 Bombard which has 6,633.85 Alloy Armor.
Now the numbers change slightly to accommodate for the new armor type.

Considering those, the first heavy attack would do approximately (assuming no statuses and orange crit):
Impact:
19716 * ((300 / (300 + 6633.85)) * (1 - 0.25)) = 639
Puncture:
138016 * ((300 / (300 + 6633.85 * (1 - 0.15))) * (1 + 0.15)) = 8 017
Slash:
39443 * ((300 / (300 + 6633.85 * (1 + 0.5))) * (1 - 0.5) * (1 + 0.25)) = 721

Impact: 639
Puncture: 8,017
Slash: 721
Total: 9,377

With the slash procs doing approximately (same assumptions):
0.35 * 9377 * (1 + 0.55) * (5.9 * 2) = 60 026
60,026 True Damage per Second for 5 seconds.

The second heavy attacks would do approximately (assuming no statuses and orange crit):
Impact:
11266 * ((300 / (300 + 6633.85)) * (1 - 0.25)) = 365
Puncture:
78866 * ((300 / (300 + 6633.85 * (1- 0.15))) * (1 + 0.15)) = 4 581
Slash:
22533 * ((300 / (300 + 6633.85 * (1 + 0.5))) * (1 - 0.5) * (1 + 0.25)) = 412

Impact: 365
Puncture: 4,581
Slash: 412
Total: 5,358

With the slash procs doing approximately (same assumptions):
0.35 * 5358 * (1 + 0.55) * (5.9 * 2) = 34 299
34,299 True Damage per Second for 5 seconds.

Conclusion

Personally, I think this is the best heavy attack weapon out there. It's good versus armor (which is why you'd use it) and it gains an attack speed bonus when you kill stuff with heavy attacks.