Star Wars – Speed of the Death Star?

[I, Cosh]

...during the time that Han and co are being chased by the Empire and maybe the first day or so on Bespin. Now either Luke gets from nowt to Jedi in about a three days OR Han and Leia really took a long time shaking that Star Destoryer....

You're not missing anything.  However, I can offer you two factoids to help you come to terms with all this.  

One: Thanks to the Prequesl, Luke is now at least 1/4 Midichlorian (there, I said it), so all bets are off as to how fast he can 'master' the Force.  

Two:  The Falcon is travelling without hyperdrive from Hoth to Anoat (the asteroids) to Bespin. Now, I always assumed that these must be places in the same solar system, and when the chaps and chapesses talk about 'the Bespin system' they mean planetary sub-systems (moons around a gas giant etc.), but a painful read through Wookieepedia will inform you that 'canonically' (hiss, spit) these are separate star systems, reached on sub-light engines alone.  So the real question must be, how many years was Luke on Dagobah?

Must...not...killfile...messenger...