The Clicks is plastic fantastic while the Minimal Phone 2 is metal (+ glass?). Weight is not an issue, the MP2 is only 8g lighter, but it might feel a bit denser due to the smaller size.
The screen on the Clicks is a bit rounded compared to the flat one on the MP2.
You also have a voice key on the Clicks, which could be a pro or con depending on how much you'll use it and, more importantly, how often it will be accidentally pressed. The MP2 has a switch that can be reprogrammed, which seems really useful!
The cameras look similar on both devices, but you do have a cutout on the Clicks while the MP2 has a Sony Xperia style forehead (which should also mean better speaker quality?)
The fingerprint sensor is on the spacebar on the Clicks, but on the MP2 it's on the side. I personally prefer on the side button, but either work.
The MP2 has a notification LED that can be configured per-app!!!
As for I/O, They both have 3.5mm jacks, hooray!! The MP2 does not have microSD card slots (they are transparent about this), but the Clicks does. The MP2 supports USB3 (5Gbps) and DP over USB-C, while I can't find the specs of the port on the Clicks website (so I'm assuming it is USB2, please correct me if it was mentioned in a promotional video).
They both have a squareish aspect ratio (the MP2 is 40 pixels taller, but basically identical) and the software looks a bit different: Niagara Launcher on the Clicks and a custom solution on the MP2 that looks a bit nicer, both run full Android though.
The MP2, as you have said, is more open with an unlockable bootloader, while the Clicks makes no mention of this. Both work with any carrier.
They both use the same Dimensity 8300 chip, they both run recent Android, 12GB of RAM, etc., so there shouldn't be significant performance differences
I would rather go with the MP2 if I did need the physical keyboard, it looks to be more open and has a nicer build. USB3 + DP over USB-C, the programmable switch, and notification LED is also really important for me. The storage is not expandable on the MP2 though, but realistically you're not going to be using much on this kind of device I feel like (goes up to a 512GB config if you need it)
You also have the fact that the Minimal Phone is in its second generation, while this is Clicks' first device, so support might be a bit better. In both cases though, they are relatively new companies, so keep that in mind. They both have a 1 year warranty.
I also feel like Clicks is a little shady, the website shows a "starting price" of $199 (when that's just the deposit, not the full price of $499), and it's very difficult to find some of the specs for the thing (it's not nearly as detailed as the MP2's kickstarter page). You also have the whole supported by an influencer marketing that doesn't do it any favours. Neither is particularly great in terms of reputation, but Minimal seems more transparent than Clicks in my opinion.
I am moving to Piefed at scallisto@retrofed.com (https://retrofed.com/u/scallisto)