There is finally a decently working Bitcoin Core GUI (bitcoin-gui)

It seems that there is now a new GUI program of Bitcoin Core - bitcoin-gui. I noticed it when I was about to compile Bitcoin Core from source. It was not very well described anywhere but I found some information that it's a new multithreaded or multiprocessing client. That sounded interesting so I tried it.

And it really seems to make a huge difference in comparison to the old GUI client (bitcoin-qt). Finally there is a client which does not completely stall its user interface for minutes at a time when it's synchronizing. The GUI seems to work properly all the time no matter what it's doing.

My earlier experiences were very disappointing:

I started Bitcoin-qt 31.1 (from Fedora linux repositories). First it gave a pop up message, stating that a wallet can't be found and it's likely so because a legacy wallet must be migrated.

So I chose the "migrate wallet" option from menu. A pop up window with a progress bar appeared but it took forever to "migrate", not sure what it was even doing. Then I closed the migration window because I thought that it was stuck. But suddenly, after some time, it gave a message that migration was successful?? Was the migration function stalled when the client was synchronizing, just like the GUI stalls like that??

Hard to trust my wallet to a program that behaves like this.

Then after syncing for some time, there was an error message about disk space being too low. But about 60% of disk space was actually free (more than 1 TB free). I suspect that there was an error with the disk itself because my Monero blockchain corrupted at the same time. But why did Bitcoin-qt give such a misleading error message??

I thought that the blockchain was probably corrupted now so I started Bitcoin-qt with "bitcoin-qt -reindex". It went through the first stage fine, but during the next stage it stalled completely at some point, and there was again an error about disk space being too low, in the debug log??

At that point I thought that it's better to download the blockchain again from scratch (files are probably corrupted and -reindex takes forever anyway) and also decided to compile the client myself, not trusting what Fedora packagers had made.