Thanks a lot for the incredibly informative replies!
The only cons for me are the compatibility and the resource loading. My target audience aren't youngsters, but adult people in their 40s-50s, which appear to use IE, unfortunately. So I don't exactly know what to do yet.
I will look into the image loading, thanks! I really hope it works otherwise it's a no-go anyway.
In an attempt to tackle incompatability, is there some kind of way to display "Your browser needs to be upgraded to view this site" message when people are still stuck on the old IE versions?