Technically benefits or reasons for using ahk v2 over v1.1

[Blackholyman]

I have been looking at http://ahkscript.org/v2/v2-changes.htm from time to time

But Other then practical reasons like that commands now also has a function counterpart and ofc Legacy Syntax being Removed...

Is there some enhanced performance, lower size, easier source maintenance maybe or some other typically important details worth knowing about...

As i like the idea of v2 but if compatibility with the script i have made in the past will not really benefit from being upgradet then i'm unsure of the right time to start using v2 full time

Sure its just me not seeing it...

[fincs]

Is there some enhanced performance, lower size, easier source maintenance maybe or some other typically important details worth knowing about...

Yes. The removal of legacy stuff removes bloat (which translates to all the effects you have mentioned). This includes legacy syntax, legacy commands and legacy quirky behaviours.

i'm unsure of the right time to start using v2 full time

You'll want to use v2 for new scripts once the v2 syntax/feature set becomes stable enough. Old scripts (especially massive old scripts) can stay in v1.1; you'll only port stuff if you need it for a v2 project.