You need to ask yourself if you need that much real-estate.
If you are only cooking for the family a Lang 84 is way to big of a cooker. I believe the product that comes off the Lang 84 is better when the cooker is filled with a lot of meat as the natural humidity helps the entire process. Heck, if the price is really good you may not worry about anything else and just go for it.
I love my Langs and the 84 holds a ton of meat. We do catering jobs so for me it makes sense. I can tell you that I never use it to cook for the family at home, but I am lucky enough to have other options.
The 84 heats evenly and needs to be fed every 30 minutes. Fire management is easy and the BBQ that comes off the cooker is great. If you are feeling lazy you can get a charcoal basket from XXL Charcoal Baskets. This will by you a few hours burn time before you need to worry about the fire. I've have one and it works great for those times when you need a little shut eye.
No mater what happens, a Lang 84 is a fun toy to have.
Feel free to PM me if you have questions.
Good luck with your decision.