I test zapx but xui one is the best
I have to greater or lesser extent used these panels. they all have strong points and weak points
Xui one is good, but has some minor problems, nxt. as well, xtream ui and variants have too, 1 stream same thing...... and the list goes on. They are all based, to some extent on the original now defunct xtream codes, which had bugs as well. It really depends what you want to do with it.
If you use mag/stalker devices, xui one will have some problems that can be an issue, hls could cause issues as well, however with lines, restream and security its top, I find zap speed could be better. Xui one is now a discontinued product and is getting outdated. Last core update was in 2022, although they did issue a security update recently to patch a hacking problem.
Xtream ui is the user interface created by GTA to control the xtream codes core and became popular after the 2019 xtream codes takedown. un modified it lacks security, especially because its actually running xtream codes v2.9 from 2019 and thats now very old, so many patches and manual changes needed, and there is a limit to what one can fix on 6+ year old code, but projects like oden have sort of kept it alive.
The above software can be had free or cracked, but patches and fixes need to be applied and you will have to be ready to figure problems out yourself.
On the other hand, projects like nxt and 1 stream are paid and license based, with active support.
NXT its expensive and also uses a cms to control the system (similar to the original xtream codes), so your gui resides on servers that belong to the panel vendor and you will loose control of your system if they have problems or get taken down (thats what ended xtream codes in 2019). The panel had quite good support, but after legal problems last year, things are not the same, they also put up the price to 500 or 1000 euros per month. Quite a few users have moved to xui one or some other panel since. The cms was also down for short periods of time on occasions during the legal issues.
1 Stream is an on going paid project with support, however many complain that its very heavy on resources, I have used it for some time and that pretty gui is quite clunkey and slow, its like beauty vs functionality, were they give more importance to looks. I also recall 1 stream had problems with ondemand channels and some other stuff, but that could have been fixed by now. Its being heavy could lead to money being spent on powerful hardware that would otherwise not be required. We also do not know if the software would continue to function if the license server had to be taken down (due to legal action or other reason), even though its not cms based.
So its best to try, then decide what's best for you.