the location is alright for easy walking everywhere and public transport. but both are on very busy streets (at least during the day), beranek with a tram line in front as well...

I would go for Beranek - as said above both hotels are on rather busy streets literally just a block away from each other.

But Tivoli is on Sokolska - VERY VERY busy street, actually a highway, difficult to cross, noisy and dirty.

Beranek has nice big street level lobby, is on cobblestone street (though not quiet either), park across and there are many little stores, cafes and reatsurants around - its bordering of residential Vinohrady.

Both hotels have the same excellent access to public transportation.

Hope it helps. Google map the location - you will see for yourself.