Yeah, I have to echo all this sentiment.
Unifab really does not seem to be an improvement over DVDFab Converter.
Let's look at some issues:

Here we've got DVDFab 12 Converter. Loading in a file loads all the info after scanning, just like Unifab so far, although note the toggle on the right. That's handy. You'll see later.
I can Choose my format by hitting that dropdown by the image, and have some frequently used ones pre-selected, or I can choose to use another profile. When I choose another, I get a whole host of options:

14 options in MP4 alone, including 10bit options for non-4K, etc. I don't need to tweak some of these, I can just select them.
By comparison, let's look at Unifab:

8 options for MP4. That's it. Same with MKV. And so on. If I want say, H265, I'll need to edit that in settings AFTER selecting a format.
In DVDFab, I can save my profiles and it'll be in the list of them:

The flaw with this one is it tends to NOT use the bitrate I set for the profile. I mean, why create a profile, including bitrate, if it won't USE the settings I saved? But anyway...
I also want to echo the sentiment above about Bits/Pixel slider.
[quote]The "Bits/Pixel" option is missing in UnFab. This was my preferred method of controlling video quality. In UniFab I must now attempt to calculate a bitrate to control video quality.[/quote]
In Unifab, I had set my profile the way I wanted it, but when choosing Personal? Not even there the next time I loaded the app:

I had to choose one of the Video profile presets, then choose "Settings" and edit it to the way I wanted again.

Then I saved. And oh, wait:

Oh really? And yeah, it's definitely already saved. More than once:

After saving (again), it's now in the list of Personal profiles, until I close the app and restart it later. Then nothing is in Personal anymore. But they are still saved as shown above.

So now I go ahead and start the conversion.
In DVDFab, when it's completed, it has a popup and the task view remains also.

After you acknowledge the main window still retains the file. Note the toggle on the right side of it? Now it's off? I can review the file I made. If I'm not satisfied with it, I can click that toggle, make adjustments and Start the conversion again.

In Unifab, not the same at all. When you click start, it moves the project to the Workspace

When it's completed, it is ONLY in the workspace. If you go back to the Converter tab, it's now empty:

If you need to re-do it for whatever reason, you can't drag it back to the converter tab. You need to re-open and re-scan the file, then choose profile again, etc etc.
Occasionally in DVDFab when converting a 4K HDR file to a lower bitrate to reduce file size, the conversion doesn't work. When playing it starts off with green splotches and the video will have issues from graphical glitches to the image stopping while the audio continues. Going into A/V settings allows me to turn off Lightning Shrink and set it to Software, but there are obviously other options you can make here:

In Unifab, every single time I have done this type of conversion so far, it has resulted in a bad conversion requiring me to change the setting. But in Unifab, the options are much more limited:

I've also tested the Unifab's Enlarger AI to upscale a video from 576p to 1080p. The resulting file was not smooth, kind of jittery to watch. I tested multiple options to see if I could clear that up, and no matter what options I selected, from bitrates, to fps, and everything in between, the resulting video had the issues.
I've also noticed that Unifab never really seems to use my GPU for conversions. All load seems to be CPU. As shown above, it clearly detects my 4070ti, but conversions never seem to show any usage while CPU percentage is shown. As such, conversions seem slower.
DVDFab would remember the last profile I was using with each new run of the program. So I only had to select a profile if I wanted to convert to a different format.
Unifab makes me choose the profile with every run.
Lastly, nothing in the licensing indicates if it's the Unifab Video Converter or Unifab Video Converter Pro that I got with my license. So many features were missing from DVDFab vs Unifab that I thought the license I was given with my upgrade was only regular, so I wound up paying $105 after taxes yesterday for the Pro version, just find it was exactly what I already had. If that's the case, I'd like my $105 back.
If I want the HDR Upscaler or Audio Upmix I have to buy each of those separately. Was the HDR upscaler part of those original 14 profiles in DVDFab, that are now down to 8 profiles in Unifab, and none of which list HDR on the 1080 profiles?
And lastly?
Like my complaint about the custom profiles in DVDFab Video Converter not using the bitrate I set in my custom profile and overriding it to whatever? I've already seen Unifab do the same thing. My bitrate set to 1394, and when loaded, it changed it to 1382. As I complained about before, what is the point of being able to set these if your program is just going to ignore them and do what it wants?