I updated my math to the correct 60% total hit rate. I edited the original post and reposted here. Ultimately conclusion didn't change just the margin.
UPDATE: I was assuming a 65% hit rate instead of 60%. tht has been fixed.
Lets check a few of these
First: TM has noted a DPR of 65.84, compared to the next highest 58.3 for the Barbarian. So that's our starting place.
1) Does Pact of the Blade count for "feat proficiencies"? An excellent question that should get clarified; I would probably agree that it doesn't myself.
2) 100% uptime on spirit shroud, I agree thats tough. In a 3 round combat, I would assume uptime of 2 rounds.
3) Eldritch Smite on every crit, how reasonable is that? So I would assume two 3 rounds fights per short rest. Over the 6 encounters per day we are supposedly supposed to have, that's 18 rounds or 54 attacks. If we maintain our uptime numbers from number 2, we need 1 spirit shroud a fight. So 6 shrouds. We have 9 slots + 2 for our new magical recall ability, 11 slots. So we have 5 slots to spend on smites over the course of the day.
Alright lets redo the math with these new assumptions.
2d6 + 5 (Base Greatsword) * 55% +
4d6 + 5 (Crit) * 5% +
1d6 (Lifedrinker) * 55% +
2d6 (Lifedrinker Crit) * 5% +
2d8 (Spirit Shroud) * 55% * 2/3 (2 out of 3 rounds) +
4d8 (Spirit Shroud Crit) * 5% * 2/3 +
5 (Graze) * 40%
6.6 + .7 + 1.925 + .35 + 3.3 + .6 + 2 = 15.475, 15.475 x 3 attacks = 46.425.
A crit with an eldritch smite is: 12d8 (eldritch smite crit). Now the next math is complicated which I'm doing in excel. But assuming we can get up to 5 crits over over 54 attacks (more than 5 crits = 5 crits for this exercise). Our damage is:
Divided over the 18 rounds of combat: 7.87
New Bladelock DPR: 54.30
So still pretty close to the barb, and technically we haven't considered the various advantage options we could have, or any subclasses. Lets do an easy one. The Celestial warlock gets to add +5 radiant damage once per round if your doing radiant damage innately (which there are several ways to do that with this bladelock).
93.6% chance at least 1 of my 3 attacks hits, so .975 * 5 =
Bladelock (Celestial) DPR: 58.98
Barbarian (Berserker) DPR: 58.3
Even taking your objections to account (which I do agree with), it still seems like Bladelock is king of the hill.