IMHO I feel the handle/grip on 12v Fuels are slightly fatter than either the 18volts or the brushed 12v tools. I noticed the difference right away. when I started on the M12 fuel line. Its not much of a difference but I actually find the brushed 12v and either 18v line slightly more comfortable for a smaller hand.
So I'm also thinking a 18v brushless compact kit might be a great compromise in size, weight, and power. But the fit and finish of the brushed 3/8 drill, impact driver and 2 speed screwdriver is nothing to overlook either, and could probably get all 3 tools for the price of 2 pc fuel combo too
Still since your building on the 12v line you cant really go wrong with the M12 Fuels from any performance standpoint. The drill is a real powerhouse plus 1/2 chuck but also I favor the hex screwdriver for balance, it has same body as the drill just shorter.
And of course I like ALL of the 12v Fuel impacts as well
Well I bet I didn't make THAT any easier hey!