Here's a sample combat log from a fight I had with a level 71 Nethermine Flayer. This is a non-elite mob that I kill frequently for a couple netherwing daily quests.
The particular mobs hit fairly hard, and are weaker from behind than from the front (as are most mobs who can Block). My strategy is to stealth up to them, distract them to turn them away from me, cheap shot them which stuns them, use a Slice and Dice with my two Cheap Shot combo points, and then start building up more combo points with Sinister Strike. When the mob comes out of stun, I Kidney Shot them to stun them again, run behind them to attack from behind again, and continue to SS them until they're dead, with perhaps an Eviscerate near the end. The Slice and Dice will last the entire fight.
If a wandering patrol mob comes along during the fight, as they often do in these caves, I'll pop my Core of Ar'Kelos and turn on Blade Flurry in order to take the second mob down at the same time.
I could kill them a little quicker (and thus increase my DPS) by using an Eviscerate instead of a Kidney Shot halfway through the fight, but as I plan on killing as many of these as I can in a row without stopping for a break, I choose to stun them a second time in order to take less damage.
Note that in this fight, my Mongoose did not Proc. This is typical, as it's a 12 second fight, and Mongoose procs once per minute on average. Also, I used a spreadsheet to calculate the stats at the end.
1/17 20:38:16.646 You perform Distract on Nethermine Flayer.
1/17 20:38:19.657 Stealth fades from you.
1/17 20:38:19.941 You hit Nethermine Flayer for 196.
1/17 20:38:20.225 Nethermine Flayer is afflicted by Cheap Shot.
1/17 20:38:20.492 You gain Aura of the Crusader.
1/17 20:38:20.492 You crit Nethermine Flayer for 303.
1/17 20:38:20.914 You gain Slice and Dice.
1/17 20:38:20.918 You gain 15 Energy from Combat Potency.
1/17 20:38:21.312 You hit Nethermine Flayer for 203.
1/17 20:38:21.596 You crit Nethermine Flayer for 262.
1/17 20:38:21.880 Nethermine Flayer is afflicted by Deadly Poison VII.
1/17 20:38:21.880 Your Instant Poison VII hits Nethermine Flayer for 171 Nature damage.
1/17 20:38:21.887 Your Sinister Strike hits Nethermine Flayer for 328.
1/17 20:38:22.167 Nethermine Flayer is afflicted by Deadly Poison VII (2).
1/17 20:38:22.450 You hit Nethermine Flayer for 201.
1/17 20:38:22.717 You crit Nethermine Flayer for 261.
1/17 20:38:23.036 Your Instant Poison VII hits Nethermine Flayer for 160 Nature damage.
1/17 20:38:23.903 You hit Nethermine Flayer for 212.
1/17 20:38:23.903 You crit Nethermine Flayer for 273.
1/17 20:38:24.188 Cheap Shot fades from Nethermine Flayer.
1/17 20:38:24.472 Nethermine Flayer suffers 94 Nature damage from your Deadly Poison VII.
1/17 20:38:24.773 You crit Nethermine Flayer for 285.
1/17 20:38:25.041 Nethermine Flayer crits you for 507.
1/17 20:38:25.041 You hit Nethermine Flayer for 219.
1/17 20:38:25.495 Your Sinister Strike crits Nethermine Flayer for 784.
1/17 20:38:26.045 You hit Nethermine Flayer for 154.
1/17 20:38:26.346 You hit Nethermine Flayer for 198.
1/17 20:38:26.630 You are afflicted by Shred Armor.
1/17 20:38:26.630 Nethermine Flayer is afflicted by Deadly Poison VII (3).
1/17 20:38:26.900 Nethermine Flayer hits you for 266.
1/17 20:38:27.132 You hit Nethermine Flayer for 109. (51 blocked)
1/17 20:38:27.405 Nethermine Flayer suffers 187 Nature damage from your Deadly Poison VII.
1/17 20:38:27.405 You crit Nethermine Flayer for 402.
1/17 20:38:27.685 Nethermine Flayer is afflicted by Kidney Shot.
1/17 20:38:27.686 Nethermine Flayer is afflicted by Deadly Poison VII (4).
1/17 20:38:28.187 You crit Nethermine Flayer for 289.
1/17 20:38:28.688 You crit Nethermine Flayer for 421.
1/17 20:38:29.925 You crit Nethermine Flayer for 312.
1/17 20:38:29.925 You miss Nethermine Flayer.
1/17 20:38:30.227 You gain 15 Energy from Combat Potency.
1/17 20:38:30.227 Nethermine Flayer suffers 188 Nature damage from your Deadly Poison VII.
1/17 20:38:30.463 Kidney Shot fades from Nethermine Flayer.
1/17 20:38:31.014 You crit Nethermine Flayer for 301.
1/17 20:38:31.014 Your Sinister Strike hits Nethermine Flayer for 307.
1/17 20:38:31.286 You hit Nethermine Flayer for 199.
1/17 20:38:31.286 Nethermine Flayer hits you for 260.
1/17 20:38:31.286 Nethermine Flayer is afflicted by Deadly Poison VII (5).
1/17 20:38:31.289 You have slain Nethermine Flayer!
1/17 20:38:31.625 Nethermine Flayer dies.
1/17 20:38:31.625 You gain Aura of the Crusader (20).
1/17 20:38:31.716 You gain 15 Energy from Combat Potency.
1/17 20:38:32.270 You gain Remorseless.
1691 (24.09%) - White Hit (9 Hits)
3109 (44.29%) - White Crit (10 Crits)
4800 (68.39%) - Total White Dmg
1419 (20.22%) - Sinister Strike (2 Hits, 1 Crit)
331 (4.72%) - IP Damage (2 Applications, 2 Damage Procs)
469 (6.68%) - DP Damage (5 Applications, 3 Damage Procs)
165.5 - IP Dmg per Application
93.8 - DP Dmg per Application
7019 - Total Dmg Dealt
11.97s - Fight Length
586.48 - DPS
1 Miss, est. 188 Damage Lost (White Hit Damage / White Hits)
+45 Energy from Combat Potency
1033 Dmg Taken (3 Hits)
As I can see from this small sample, I'm likely better off wielding dual Instant Poisons for all fights that last less than, say, 15 seconds long. It's harder to apply Instant Poison, but the Deadly Poison damage takes time to accumulate.
Also, these numbers support the 1-Roll theory of combat. In other words, you don't need to Hit to Crit. Hit is better for rogues in that it allows more procs, but having a Relentless Earthstorm Diamond as your helmet Meta gem will make Crit almost equal to Hit. Again, though, things depend on your equipment and style. If you've got a trinket that procs on Crit, then you may want to boost your Crit a little. Hold on to that Hit gear, though, as you may find a better trinket down the road.