Choose.....
Good morning Federico,
The visibilty is better with the tip-up canopy because the roll bar is behind you. The slider looks better when it is open, in my opinion. When the tip-up is open and the wind blows from behind, it can strain the lift struts some.
I don't think that the slider is necessarily safer because in either case, if you ever end up upside down, you'll more than likely need to break the canopy from inside with an axe or other tool. Kinda your choice,
Regards,
Pierre