How exactly does Forklift compare, especially the newest version?
Sorry for the late response; I didn't notice you asking me this question about how Forklift compares to QSpace.
Forklift seems quite simplistic compared to QSpace. It has far fewer features from what I can tell testing the latest Forklift 4. Forklift is very Apple-like in trying to keep it simple to avoid confusing the user. They focused on form over function. The result is you get less features. From what I can see, compared to Forklift 3, most of their efforts were towards making the app prettier.
Forklift has a significant failing if you use List View. Forklift, Finder, PathFinder, QSpace all have a List View - a view where you can expand the directory structure and see the contained files and folders. Only Forklift provides no way to remember the expansion of the directory structure as you left when you last were viewing the top folder. Every time you revisit the folder, it shows as fully collapsed. You have to re-expand everything to get back to the way you were before. That makes Forklift completely useless since I use List View almost exclusively. When I discussed this with Forklift support a very long time ago, before version 4, they agreed it would be a good thing to add.
QSpace is very sophisticated in retaining the state of any folder. You get a toggle which allows you to set any folder to retain its full state. So you get to retain the tree expansion, sort order, etc. It's completely at your discretion which folders you do this for. QSpace understood the importance of that and prioritized it. Forklift deprioritized it.
An amazing feature of QSpace is the configurable context menu, the menu you get by right-clicking on a file or folder. You can add almost anything to it, even custom actions you define. I'm so tired of launch services failing to give me the program I want when I select "Open With". In QSpace I have the programs I use most ready to handle any file. Forklift just doesn't have this feature.
QSpace has configurable layout: 1, 2, 3, or 4 panes placed in many different ways. I have many workspaces, each with different layouts. What a loss it would be to use Forklift and be stuck with one or two panes.
Speaking of workspaces, QSpace did a much better job at it than Forklift. Workspaces are first-class citizens, not just entries in your favorites. When you switch to a workspace in QSpace, it tells you what workspace you're in. As you navigate around in any of the workspace panes, the workspace is updated to retain that state for the next time you go back to the workspace. If you want a workspace to be locked in, you can use the feature of QSpace which allows you to lock a pane to stay rooted at a particular folder. That lock state is retained per workspace.
QSpace has so many other features. This has a downside in that you sometimes don't know what a feature mentioned in preferences actually does. There's no help menu. Also, their online tutorial is quite limited. They usually have no tooltop on the checkboxes in preferences. So, it's a learning curve.
They quickly addressed bugs that I've reported. They also have frequent updates.
I don't like the China angle. However, they don't even try to hide it. I really don't know where a lot of my software is actually coming from, what ties to particular countries exist, or what the privacy laws are in each country involved. (I guess I'm too lazy to spend the time; it would be quite the undertaking.) On Windows I used to run Kaspersky. I stopped because it was from Russia; I switched to an alternative that was just as highly regarded. Unfortunately, I haven't found any alternative to QSpace that I regard as highly.