I've used the Asic Cumulus for a long time and until the 19, were always magic for me.  However the 19 toe box was very tight, they seemed shorter, and they did not have that magic Cumulus cushioning.  Wont get into it all here but bottom line developed hip issues and lost a toenail.  Did go back to my old worn out Cumulus yard shoes, and they so much better.  Crazy!  Decided to try these out.  For me they seem to fit as expected, but I do not ever recommend buying running shoes online.  Support the stores that let you try them on, run around the store and give you feedback.  Worth the extra $5 in tax.  The  cushioning in these are very good but not at the level of some of the higher cushion models, or the older Cumulus.  But these are lighter and have a good sprig to them.  I've backed off on running and was willing to sacrifice some cushion for a lighter shoe with a lower heel rise to get a good all around workout shoe.  These are awesome!  Roomy toe box with very stretchy material, but I do not get heel slippage, best breathability I've had, not too much heel rise so nice and stable for balance exercises, and an excellent running shoe. Even good looking