it's going to be kind of artificial: the Beatles could be spontaneous on stage; but a Beatles tribute band wouldn't be because their business is only in replicating what the Beatles did do.
On the other hand, these acts mostly spring up when the originals are no longer playing; so a tribute band may be the only chance you ever get to see the music performed live.
So over to you - how much did you love Queen, how much did you admire their music, how much do you want to see someone else playing it?