Can I use GMS2 for a real project or is there anything missing from the previous version? Is it stable enough?
Affect it, yes... Break it, no. I would use GMS2 over GMS1 for any type of project (be it hobby, concept, or commercial) any day of the week. And many do this already, with large existing projects they imported from GMS1.I'd personally wait to use GMS2 for production as things are being changed and added to it and some of these changes could possible affect anything you've already created in GMS2.
I do agree with you, but there are a lot of quality of life changes that I can't ignore. Version 1.4 is a very archaic tool.There will always be bugs. That's not the point. However, in an actual production it is not the wisest course to choose to use beta software, be it for creating graphics, code, or whatever. It's not just bugs. It's changes that can take place (i.e. possible code changes, etc.) that can affect you in the midst of a development cycle causing you to 1) have to go through everything you've done and have to make changes (changes that you normally would not have to make with non-beta software) or 2) causes things that once worked to no longer work (or no work as intended).
But bugs in beta tend to be harsher than most of the bugs once software reaches GC (Gold Candidate) or is ready for release. Unintended memory leaks and a slew of other things can bring production to a halt.
I fully recommend testing and learning and working in the GMS2 beta. I do not recommend going full production in it until it is at least GC. But that's me (and most people that use software for a living).
But considering GMs 1 has just as many bugs if not more...Sorry, despite all that has been said here, it is never a good idea to go into production with a product that is marked as beta. You can do it. People do. But it's just not a good idea. There's a reason it's in beta. Once again, once it's GC, go for it. Beta. Nope. Learn, play, prepare, but don't go into production. Of course, you all can do as you please. No one is stopping you ...