Neighbor just bought 2 of these for his garage,
https://nationalautotools.com/products/c7000-portable-two-post-auto-lift
I think if you only need it for occasional work the 4 post is a better option,
but if you are going to be working on anything more than 2-3 times a week, I think your better off with a 2 post.

For me the deciding factor for 2 versus 4 would be if I planned on doing frequent tranny or rear end work (swapping rear ends). If I was doing lots of either, I would go with a 2 post. I have a 4 post and agree with all of the positives and negatives listed so far. I have a rolling jack for it so brake and suspension work isn't an issue. A tranny can be pulled on a 4 post but definitely a little more of a pain. Exhaust work can also be a little more challenging when doing headers, but not insurmountable. I use mine to store my trailer indoors when its not in use so I like the extra height walking underneath without having to worry about hitting my head on hanging suspension. I have a Direct lift and moved the safety stops as high as I could so even a 6'+ person can still walk under without ducking.

Another vote for 2 post. I agree with most of what's been said so far - 2 post takes less room and allows more access under the car. IMO, a 4 post isn't good for much except storage. A 2 post can be used for short term storage too. If you have the height, 2 post is best.

As for what was mentioned about having doors open while in the air - I'm not sure that's terribly relevant because in general, you wouldn't have the doors open while the car is up in the air. Besides, you can open them depending on how the car is set up. If the doors are open, it's probably best that the car is on the ground anyway.

Someone mentioned that a 2 post lift can be tougher to get a car on which isn't really a fair comparison. Backing a car off a 4 post lift can be tricky sometimes if you have limited sight lines or obstacles around the lift. Sliding the lift arm underneath the car is not hard unless you have mobility issues or the car is really low. Even if it's low, you just use little blocks to raise the car up a bit before sliding the lift arm under. Once you do it a few times, it will become second nature. You could even put some sort of mark on the floor or wall so the car is in the same spot every time.

2 post is also good for attaching an air hose reel so you will have easy access to it.

But whatever you do, don't buy a cheap off-shore one!

2 post for sure... have used both and I'd never consider buying a 4 post for anything but storage.

I have a two post, never wanted a four post.

What's your ceiling height? Will you be able to open the garage door with a car on the lift?

I bought a used two post lift in '95....a 70's vintage 9k unit. Very heavily built...still working great after all these years.