You need to run temps several places on your cookers and chart them.
Your spots on the racks could run up to 50º different-when empty,just like a stickburner.
You can get lots of discussion about all the things, besides chunks.
COLDSMOKING, you could use sawdust,shavings,etc.
Other than that, stick with 3,or 4 golfball sized chunks for EVERYTHING you cook,until you get a feel.
You can cook 125 lbs of meat for 24 hrs with 8 oz of chunks.
You may add an occasional chunk, at different times in the cook,just like on a stickburner.
I would NEVER,EVER consider using pellets.
150 does great on most things a commercial operation would serve.
It is a very moist cooker,since it flows much less air than a stickburner.
You can force more smoke on product,than your FEC will allow.
If you demand a smokering,toss a couple KINGSFORD briquets in with the woodCHUNKS.
We cook comps with our FEC s,but would love to be able to do them with the 150.
If you hotcook chicken,so you can fry the skin,you need to get up closer to 350º-so comp cooks sometimes use the FEC.
As to best,just my personal opinion-coldsmoking,jerky,cheese,shellfish ,bacon,etc it would be better than the FEC.
Yes,if you want only very light smoke on shellfish,poultry,etc,you can run the wood box empty.
Think of it as a house oven.