[ptx]

Which problems are those?

One problem I usually have with GUI builders is that they generate huge and messy data files for the layout which can't be meaningfully diffed. Visual Basic is even worse because the form files are binary blobs. Lazarus seems to use fairly concise and readable plain-text files for its forms, although there's also some sort of binary resource files.

[speed_spread]

You'll have the same issue even with hand written code? I'd say the solution is that we need semantic diffing to show GUI changes.