I dont have rocket installed atm, so 20 seconds was just a guess. Waiting for the next version.

But for me (and my 3G connection isnt great) it does take that long because the application has to load, and once i get past the splash screen then the tweet has to load fully before i can click on a link in the tweet.

I am not blaming the developer, i just prefer to keep rocket running in the background to avoid this issue. But if i do, it doesnt update the homescreen