Update 2:
(Adding our Langer’s visits to this Langer’s thread as well, for reference.)
Matzo Ball Soup:
Langer’s Matzo Ball had a soft, pillowy texture, but it was a touch more zesty and savory for the Chicken Soup (compared to Daughter’s Deli).
Hot Pastrami Sandwich (Mustard):
Taking a bite it was apparent immediately what the difference was between the OG Langer’s and Daughter’s Deli:
Langer’s Pastrami Sandwich has the same Rye Bread - soft, with a crusty exterior crust - but the Pastrami meat was actually hot (not cold), and it was definitely more savory: There was a more noticeable Salt & Pepper (and other Seasoning) aspect to each bite. It’s more aggressively seasoned, while not being too salty.
It was delicious! 
Everyone in the group agreed, the flavoring is just better at Langer’s and it’s served hot.
#88. Hot Corned Beef, Sauerkraut, Swiss Cheese Grilled on Rye Sandwich:
Same here: You’re greeted by a toasty, crunchy Rye Bread exterior, giving way to hot Corned Beef, melting Swiss Cheese and Sauerkraut tang. So good! 
And the Corned Beef tasted a bit more seasoned as well.
Additional Visit:
Barley Mushroom with Giblets Soup:
I really liked the Barley and Mushroom combination, a bit thicker than their usual Soups, and you got a small bit of meatiness from the diced Chicken Giblets. 
Fried Half Chicken:
I spotted “Fried Chicken” on the menu out of the corner of my eye, and I think somehow in our 15+ visits to Langer’s we might not have ever tried it. Out of duty to FTC and our Fried Chicken Journey, we had to give this a try… 
The batter is lightly crunchy, not crispy, and it’s got a zesty seasoning, reminding us of what a decent Roadside Diner might whip up if they had Fried Chicken on their menu. The Chicken meat itself was fine, the Chicken Breast slightly overcooked. It sort of scratches that itch for Fried Chicken, but it’s not upper tier at all.
Fries:
Their Fries arrived piping hot, which is always cause for joy. Langer’s Fries are perfectly fine, probably from Sysco, a Crinkle Cut variety, but when you get them fresh out of the fryer, lightly salted, they are just little bites of happiness.
Steamed Broccoli:
We had to get some veggies during this Pastrami exploration.
#19. Pastrami, Swiss Cheese, and Coleslaw, Russian Style Dressing:
And we have Langer’s (in)famous #19 Sandwich, which they proudly proclaim as their most popular dish on the menu.
Taking a bite, you get the soft double baked Rye Bread, the Coleslaw, Russian Dressing definitely add a similar sweetness / slight tang, but at Langer’s their Pastrami is served hot, and it’s more savory and better seasoned, so that definitely helps make the #19 more palatable and tasty than the Daughter’ Deli version.
We were dividing up the Sandwiches into quarters / sharing bites since we were doing bang x bangs. However, even at Langer’s, I couldn’t finish my quarter of the #19 Sandwich. 
I just couldn’t do it. The #19 feels so wrong on so many levels, LOL. Forgive me FTC! I definitely prefer Langer’s OG Hot Pastrami, Double Baked Rye and just Mustard. That’s all you need to enjoy greatness.
Another Visit:
Hot Pastrami Sandwich (Mustard):
Just perfect, yet again: The Pastrami arrives hot, it’s luscious, tender, moist, has more seasoning, a touch saltier and zestier (and I don’t like too much Salt in general). Everyone in our group devoured our Sandwiches in what felt like a few seconds. SO GOOD!
#88. Hot Corned Beef, Sauerkraut, Swiss Cheese Grilled on Rye Sandwich + Russian Dressing:
I remember one of our FTC’ers lamented that Langer’s didn’t have a traditional Reuben on the menu, so we ordered a #88, and asked for Russian Dressing on the side (and added it in ourselves). While not exactly the same, it was pretty close at this point and tasty if you wanted a Reuben.
The #88 as is was delicious: I loved the Grilled Rye, toasty and crunchy, the Corned Beef was hot, the Sauerkraut gave it a nice piquant note and the melted Swiss added some creamy qualities.
Langer’s Corned Beef Hash:
Nicely spiced, tasting like a great Diner-style Corned Beef Hash (like a variation off the canned version), not the more recent trendier fresh Corned Beef Hash, which is large rustic chunks of Beef & Potatoes, etc. This was a great classic-style Corned Beef Hash.
Langer’s Deli continues to deliver the best Pastrami Sandwich we’ve ever tried. It’s the combination of the great double-baked Rye Bread, soft on the interior and with a crusty edge, the luscious tender hot Pastrami, and a bit of Mustard. Perfection.
Add to that a great #88, for those that want a “Reuben”-esque Sandwich, I love the Grilled Rye, crunchy and toasty, the melted Swiss, Sauerkraut and Hot Corned Beef.
And from previous visits, the awesome #44 (thank you @wienermobile), a great Eggs & Corned Beef Hash (available all day), and a few other standouts and it’s easy to see why we love coming back again and again.
Langer’s Deli
704 S. Alvarado St.
Los Angeles, CA 90057
Tel: (213) 483-8050