I'm biased. I'm a fan of Weber products (though not all) and have kettle grills, gassers and smokers made/sold by them.
Particular aspects include:
Porcelain coating that's durable enough to keep these going for decades.
Grill cover that allows use during winter months (easily down to zero F, colder if you're tough enough)
Gas igniter in my Performer 'cause I'm a lazy bastage.
Smoker designed to hold a lot of food and run a long time without much messing around.
Cast iron grates - found on property when we moved in in '87 - that are heavy and fit both my gasser and kettle.
26" kettle that can fit big things like a big turkey or lots of things like beef back ribs or chickens.
Remote reading thermometer (ET-73 and ET-732) so I can monitor a long smoke w/out running outside every couple minutes.
There's not much I don't like about grilling and smoking. My tools are adequate to the job and do not limit my results.