I own a round column mill (G1006/7) & it has served me well as a manual mill.
I've added a power head lift with a pneumatic clamping system, which makes the up / down movement MUCH less hassle.
I'm sure there's others who will disagree with me, but though I have found the power to be adequate & I liked the price, I do find myself cursing the round column & the 3 pulley belt system frequently.
A 3ph motor & VFD would help the speed changes but would add another $400-$500 to the price.
I purchased mine because Grizzly was out of stock on the G0484.
If I had it to do over again I would not buy a round column mill ..