unless you have fat toes or a fat forefoot area where the "strap" would be, staying true to size is probably a good idea.. if you wear orthotics orthick socks or like having a bit of room in the toebox or have a thick toe area, i would go up a half to full size. most of the time you will have room at theedge of the toebox but trainers are more about the room you have in the forefoot area surrounding your toes. some like it snug, some cant live with it. so itsa choice you have to make.. more forefoot room = more toebox room. some like a snug toebox. but if you have wide feet, you might have to deal with the toeboxroom being a bit excessive.. hope that makes sense
over the years ive adjusted to wear my true size, a 12, or even a fit that is alittle looser in a 13. if you have normal feet, you could honestly stay withinyour size region and be just fine.. i have an 11.5 2003 jordan III White/cement that fits like a 12 to 12.5 at1.. Most air trainers on ebay dont have halfsizes availble so jumping up a full size was just fine for me. the fact that people have a choice now is intrging.. since ive worn both sizes, i tend to steertowards the middle