If JS is disabled the form - by default - would submit to the action that rendered the page but you could set the form configuration to ‘action’=>array(‘item/delete’) so that it still will be sent to this action even if JS is disabled.
The difference is that a ajax submit button has a natural fallback (as it is a submit button within a form thus using the classic html submit when js is disabled) while the ajaxLink has none. I think you would have to implement that by yourself