I just had this same problem.
I was debating between Blue Glow Trainers $143 (half size too big) and red racers $105 the correct size.
I chose the Blue Glow Trainers half size too big and plan on steaming the to shrink them down a little.
After 3 pairs of racers and 4 trainers this is my conclusion. Trainers fit TTS and racers you should go up a .5 size. I like my shoes snug. With trainers my toes go almost to the end with a size 11 and with racers there is not enough room with the same size. This is just what works for me and other people have different opinions.
Thanks for all of your replies.
I just ordered the Blue trainers in 11.5 (half size up), I have a wide foot so they should be fine, if not I can steam them.
Also ordered Volt Lunar 1+s as well. I'll be sitting here waiting for the post man like a little kid now haha
Looking forward to posting more here, seems like a cool community. Any other Aussies here?