Sub busses (and A&H MixWizards...)

[DropD]

What are sub busses for? I'm asking that because I noticed the Allen & Heath MixWizard 16:0:2 console which cost the same price as a Mackie 1604, but gives me the superior quality and sound of a A&H, plus 2 effect processors, 2 sweepable mids, 6 aux busses, yada yada. The only thing lacking compared to the Mackie and higher-end A&Hs are the sub busses. But I just can't figure out what I would need those for...

I mean, for live monitoring and effect sends, the 6 aux are everything I need, 2 are pre fader, 2 are post, and the remaining 2 can be switch from pre to post. I see how they would be used for recording, but if there's a direct out on every channel, I don't really need them. If I need to group multiple channels on the same track, I can always use the aux busses right? (I only have 4 tracks of simultaneous recording on my sound card anyway). So, I guess I have everything I need with that mixer right? (ok it doesn't have the EQin/EQout of the GL serie, but it's also half the price!).

Also, anyone knows if a MixWizard will give me the same EQs, same pres, and same headroom characteristics of the GL serie?

Thanks!