We ordered 2 pairs of these - sz 9.5 & sz 10 - our son is currently a sz 8.5-9.5 & I read these ran small so figured we'd try both & return the one that didn't fit. Well - let me say - the difference between these two shoes is SO much more than just the size...they include:1) The size - obviously - but it's a HUGE size difference - WAY more than ½ size should be for any shoe (I often buy shoes in 2 sizes & return the ones that don't fit - the size differences are never this drastic!)2) Aesthetics: --Coloring of the exterior - significantly different shades of orange (the pics i uploaded really don't do this difference justice b/c of the lighting) --The color of the shoelaces - well technically - the shade of blue (significantly different). --The color of the word "diadora" on the insoles - one is white, the other is neon yellow3) The bottom soles - everything about the outer soles of these shoes are different - the type of cleats used, the layout to the individual cleats - the shade & type of rubber (or whatever it is) that's between the cleats, the way the sole is attached to the shoe...and lastly - the quality - the quality of the sz 10 seems far superior to that of the sz 9.5And this is just the stuff I can see...honestly - it's totally bizarre. I received the sz 10's first & we tried them on immediately - they were so big on my son that I was convinced there was no way in heck the 9.5's would fit...well they fit him perfectly (barely any room to spare). I of course checked the tags on the insides of the shoes since I seriously could not believe these were just .5 different in sizing...but the differences are so much more than that!! Which is why I uploaded the pics - there's no way to really describe how different these shoes look...it's really very strange. I also checked the manufacture date - the 9.5's were made in July 2014, the 10's were made in December 2014 (this is given on the tags inside the shoes).The big major difference is obviously the cleats & really the entire sole of the shoe...it's completely different. The 10's are attached using two rivets - the 9.5's are sewn in - the type of cleats are different...etc.Ultimately - we're keeping the 9.5's - not going to deal with trying to find another pair he'll fit (that and we need them tomorrow...so obviously not much time for that!). But will certain think twice about buying another diadora pair down the line (especially since once his feet are large enough for sz 10 in other brands the options are significantly more than they are right now!)