If i’m starting a new project, should i use the latest version?
if i already have a project, should i upgrade it?
I know u should consider if its worth it or if u have to fix a bunch of things to make it compatible, but this is more for “how stable is the new release?”
If you are starting a completely new project, there’s usually no reason not to start using the latest version. Most people have an issue when they try to upgrade their project.
The only issue you may face is that assets from the Marketplace may not have caught up to that current version.
Yes, there will be bugs in new version releases, but don’t forget that those new releases always have “mini” updates to optimize their current version’s performance and stability.
Hi, notice how many topic are there that something doesn’t compile in UE 5.3 or 5.4 
Unfortunately these versions are pretty problematic and unstable (of course depending on what features you use). For new project I think it’s good to start with the newest anyway, as sooner or later you will need to upgrade.
Regarding upgrading existing projects, if this is a real project that you want to release, ask yourself do you need any features that come with the newest version. Upgrading project is usually a big deal, especially if this is complex project. Many things can break, work differently, etc. So if you don’t need to, I would recommend not to upgrade.
I’m working on a game that will be released in 1,5 month and it’s still on 4.26 as we never needed to upgrade.