^ Depends on what area you apply for, what kind of units you have on your transcript and the type of firm - alot of variable factors which can't be generalised under one statement. I'll give two contrasting examples.
For example, a friend of mine who has a not so great transcript, but wants to work in M&A has 1) Very high scores (dux) in selective units such Investments/M&A 2) Alot (and I mean literally alot) of work experience in the M&A sector in various firms, both domestic and foreign. 3) Currently doing his honours thesis on M&A too. With those combined you don't necessarily need to have an insane GPA to get the position.
Another example is myself, I literally have no real working experience at 'firms' (apart from being a teaching associate at Monash), however because I have the academic results to back it up, the relevant units and awards etc, I've been offered interviews for GS, UBS, JPM for quant fi positions (equities/ficc). I've also been personally approached by the CEO of PwC (Luke Sayers) for their quant risk analyst positions.
But remember, the academic factor is only really for you to get that elusive interview, once you get the interview, almost all 'academic' knowledge is thrown out the window. You need to be very up-to-date regarding relevant market events, firm positions and what's happening around all financial sectors, without good practical knowledge, you will not pass the interview.