RF45 or Chinese Knee Mill.

You'll have to determine what your anticipated work envelope will be, and make a decision based partly on that. The RF45 is limited, more so than most knee mills, and the knee mill may be more accurate in the Z axis, since you're advancing the work into the cutter against the threads, instead of allowing gravity to drop the head into the work, unsupported. I have a RF45 clone, and find that I use the quill more than the Z axis, because of this.

That being said, I really like my mill, for the work I do, and have no complaints.

I have an Enco Mill/Drill and it can do a lot over the years the price has gone up quite a bit so I guess they sell very well and I have not found any bad write ups on them. Mine is a round column but works quit well once you get use to it. Best of Luck Al Kimmel

FWIW, I have a round column Taiwanese mill drill which works fine for my purposes, but I would definately buy the dovetail version if I were to do it again. I thought the round column would give me some versatility

- it hasn't.

Adding a power feed and coolant supply to an RF45 isn't hard, but it takes time. For my money, a little extra for the knee mill would be a good investment. This is something you'll have for a while, and a few extra dollars will not be noticed over time.

I have a chinese lathe that I bought a decade ago, and I have no problems with it - although a T-slot cross-slide would be nice.