I have a lang 84. I love the pit but there are some things I would like to see on it different. Meadow Creek makes a good one also. I like the added features to it that the Lang doens't have. Like both racks slide out on it and has a sliding ash pan at the bottom of the fire box so you can get the ash out of there easy while still cooking on it. Ash will build up in a Lang and cause drafting problems if you go for a really long cook or use Briquets in them. That really creates lots of ash in them.
Another thing to think about is the cooking temp. Do you want to cook everything at one temp? Then reverse flow is the way to go. Want to cook at different temps, then don't use a reverse flow - use a standard offset (like a Klose) with tuning plates so you can have different heat / temp zones. If you cook all your meats on one grill - due to necessity since you are now towing one large trailer - then you better have your timelines down so you can get your big meats off and crank it up for chicken.
Leads to another question - how easy is it to change the temp? Goes back you your original question about controlling the pit. I think it is easier to increase the temp by adding air to the firebox and / or more fuel than it is to open the pit and hope it recovers DOWN to a lower temp. You'd have to be a serious witch with that pit to do that consistantly.
What about capacity? Do you need enough room for PC? Or just Comp Meats? What about catering now that you have that big fancy pit? How many people do you want to feed and what's on the menu? What is the cooking surface are per $? All more to concider when selecting a pit.
My two cents - I use a Traeger COM 200 for all my PC and for catering. Timing is a must BUT the ability to adjust an electronic temp controller sure is nice when you want to crank it up to cook a little faster - or open the door, let it cool down, set the controller for 180 and shut it back down for a huge warming box. I use multiple Traeger 075's and a WSM 22.5 for all the Comp meats. The COM is just too big and eats pellets like crazy. This also allows me to cook the brisket at a different temp than the butt, and the ribs, and the.... well - you get the idea.