That's bad advice, as if you put at market order in, especially...

That's bad advice, as if you put at market order in, especially large orders, 80% of the time you will get the low whole offer price, not the mid-point... Even when Commsec says your order is at mid-point price, doesn't guarantee a mid-point price, trust me I have done hundreds over the years and a big chunk seem to fall to the lower than whole price not the mid-point price... Maybe small orders would have better success with Commsec as larger orders very rarely get mid-points....

What's best is using Brokers or even CMC Markets (cheaper brokerage than commsec) as you can easily place Mid-point trades and also importantly Chi-x/Cboe orders... Commsec are so restrictive and I am a commsec one client (708 investor), that's why I have transferred all my SMSF holdings to brokers and CMC, once out of 88 I will then transfer all my trust and personal holdings out of Commsec as well... Hope this helps, now back to reading....