Professional timber framers do not only need to be accurate , we need to be efficient too.
We can not only cut one rafter at a time , we need to be able to cut a roof system components at once with out handling each rafter one by one.
If we'd do that our labor proportion on our bidding would get out of hand.
And this is where the 16-1/2" Makita meets its limits. It is not accurate enouch to provide you with the efficiency as a $3000 (or more) saw does.
Compared to its costs, so, it very well is the best of its price range ( with the japanese table and a different blade).
Consequently it is to decide if you make enough money in efficiency to accept the (quite high) price difference.