Personally I would like a roof eventually over mine. The benefits for me would be for the winter cooks so the coals dont get wet during lighting (and not getting totally soaked when the food is finished). If you do or plan to do alot of low and slow, roasting, indirect cooking etc then I think its worth considering since rain would be less of a concern in my opinion. With these types of cooks I can leave the food cooking outdoors while im doing other things in the house...but this depends on how much trust and what type of bbq you have.
If you only intend to do direct cooks then I cant see any real benefit. I wouldnt do direct cooking unless its a lovely sunny day.😎
Thats my input anyway, hopefully others will share their opinions to give you some more ideas etc👍
...I have yet to build my table though so I have a long way to go haha🍻