I have both and cook all kinds of product on both.
We compete on FEC s,due to rules.
The 150/160 will peak about 300*-315*,which is pretty much what you want a smoker to do.
I can effectively add more smoke,if I wish, on the 150 series.
If I did much cold smoking,fish,cheese,sausage,etc,I would, personally, probably do it on the 150.
I can teach a novice to use the 150 ,more easily/quicker than the FEC,but the FEC is no problem.
I can pick wood up off the ground for the 150,or buy a year's worth for $15 from the box stores
You will be ordering/storing pellets for the FEC,as on the Traegar.
It probably runs us less than $0.75/hr to run an FEC on pellets,maybe $0.25 for overnight on the 150.
They both are well insulated and very effecient.
Impervious to wind,rain,cold.
The FEC will recover temp more quickly,if you have a need to open the door a bunch.
Cooking chicken wing flats,shellfish,etc it would recover,if you kept opening the door to look.
The FEC can hold temp within 2*-4*,and cook comfortably at 350*-which means you are no longer smoking.
My 150 was built in the 90's and never had a problem.
I see them heavily used,20 yrs old and no problems.
I have an older preramp FEC,and a new IQ4 FEC at home and never had a problem.
We have never had a problem with our comp units,either.
I set all to run all night and then drop to hold temps,and never look at them.
I go back to the motel.
Smokin Okie might say the FEC could be a little more versatile,if you were operating in a commercial situation.
It would really depend on some specific need.
Hope this helps a little.