It really depends on what you want, reputation is not the be all and end all:
If you care about the reputation - theres a marginal difference, but not much and the MQ Law school is becoming increasingly underfunded. Its only a matter of time before the reputation if MQ is displaced all the problems with the law school, which we students are fighting to address.
Style of teaching: MQ is philosophical/UWS is practical - which do you prefer.
Law society - MQ has a fairly active law society, UWS used to have a fairly inactive one but I hear is changing
Elective choice - look at the electives for both uni's, I wish I had considered this before the transfer.
Transport - which suits you better to get to?
Infrastructure - UWS has some nice new buildings, MQ LAW is in all the old buildings.
In terms of job prospects there isn't that much of a difference, do well, get involved, get work experience and it wont really matter. Look at the factors I meantioned above and think about what suits you better.
Having done what are you suggesting, I wish I had realised the trade off for the slightly added prestige, but these days the difference isnt that much. Best of luck