Seeing a datasheet with so many statlines made me wanna break down the mathhammer real bad. As others have noted 7 PL suggests a points cost of 28ppm or 140 for a squad of 5, equivalent to 7 Intercessors. So to begin, here's standard Intercessor options on average for a squad of 7:
Auto Bolt Rifles get 14 hits, causing 7 wounds to Primaris of which 2.3 fail armour saves, killing 1 model total at 24". They cause 9w to GEQ and kill 6.
Bolt Rifles hit 9 times, causing 4.6w to Primaris, 2.3 go through at AP1 killing 1 model total at 15". Vs. GEQ, 6 wounds, 5 unsaved killing 5.
Stalker Bolt Rifles hit 4.6 times, causing 2.3w of which 1.5 go unsaved, killing 1 Primaris at 36". Vs. GEQ they do 3 wounds and kill 3.
So we know Auto Bolt Rifles are the way to go, performing the same as standard vs. Primaris but better vs. GEQ and at longer range. Stalkers are solely for long range engagements where they wouldn't be doing anything otherwise. The new statlines look like this, for a unit of 5:
Hellstorm Bolt Rifles get 10/15 hits causing 6.6w to Primaris of which 2.2 are unsaved, killing 1 model at 30". GEQ take 4.4 unsaved wounds killing 4.
Heavy Bolt Rifles get 6.6/10 hits causing 4.4w to Primaris of which 2.2 are unsaved, killing 1 model at 18". GEQ take 3.7 killing 3.7.
Executor Bolt Rifles get 3.3/5 hits causing 2.2w to Primaris of which 1.4 are unsaved, dealing ~3 dmg and killing 1 model at 42". Vs. GEQ they kill 2.
So the takeaway here is that more shots is better as we've seen throughout the game since statlines have been revised. Heavy Intercessors are simultaneously overkill and underkill against GEQ and not a great pick vs. MEQ with their impending 2w, but their Str 5 shots do help compensate for the reduced volume of shots for the comparable points. Now let's look at the Heavy Bolter variants, assuming BS4 as they've moved since these guys are slow chonkers with few transport options:
Hellstorm Heavy Bolter gets 2/4 hits causing 1.3w, 0.4 saved so no Primaris dead. Vs. GEQ D2 is wasted and one dies.
Heavy Bolter gets 1.5 hits causing 1 wound, causing a 50/50 chance of a failed 4+ to kill 1 Primaris. Again D2 wasted on GEQ killing 1.
Executor Heavy Bolter gets 1/2 hits causing 0.6w, the AP2 can't fix the problem and statistically you won't kill 1 Primaris. Ok, you get one GEQ.
Obviously there's more we could do combining these units with each other to see the best combos and get a better sense overall, but here's the TL;DR. These guys have comparable damage output to Intercessors and the same three bands of utility. For my money though, the Hellstorm Bolt Rifle is the only way to fly since these guys will need to move as troops and their armour is likely wasted in the backline.
The Heavy Bolter variants are collectively a trap since you can only run a maximum of two in a 10-man unit, the range is probably wasted and D3 is overkill. The all-Executor loadout with 1-2 Heavy Bolters is tempting but I think you should be able to zone out your DZ from deep strike and ObSec isn't so necessary there. The best use of this squad is to close the range by moving to the midboard and withstanding a hail of shots, and the Assault variant does that best though 5" movement is a bit of a pain.
At 140pts 5x Heavy Intercessors nets you 15 t5 wounds versus 7x Intercessors which net you 14 T4 wounds - I think that is the true strength of this squad, you essentially get the same number of wounds for the points and t5 for free, with comparable impact firing at range. Intercessors still have an edge in combat as each model adds 3 attacks with Shock Assault; Assault Intercessors are obviously better than that but don't get to fire nearly as effectively while they close the distance. So:
Need a tough unit to hold an objective against a shooty army with poor CC and no board presence? Heavy Intercessors.
They have board presence and you might need to charge them off? Standard Auto Bolt Intercessors (or Assault Intercessors if you have an Impulsor fetish and good fire support).
I'm also here wondering if the other two Intercessor options will get access to the Vigilus Veteran stratagem...
