Depends on what kind of powder you're measuring. B&M is VERY good, but certainly needs to be mounted on an immovable bench. Harrell's is extremely well-made. These are good for most powders. For long sticks, like 4350 and such, the Lee, cheap though it is, is probably the best there is (short of the "automated" dispensing system called the Prometheus). The Belding and Mull is probably almost as good, as I recall (it has been a few decades since I used one). For Bullseye, of course, there are or were measures with non-adjustable rotors that are made specifically for this powder.
I use a Harrell's for my pistol cartridges (non-Bullseye), a Lee for .308, and Prometheus for my precision reloading of rifle cartridges. Perhaps I should use the Prometheus for .308, but I haven't felt a need yet, and I have no complaints against the Lee (at least for sticks).