Blundstones and redbacks are essentially the same aside aesthetic differences - both use cheaper leathers, have no shank, similar sole attachment (fused). Solovairs and MiE docs are basically the same price and nearly identical in terms of construction and materials - coated/refinished leathers, heat fused welt. Shanks arent actually going to make a huge amount of difference to most people who have sedentary/city/office based lives. Most people aren't going to bother repairing their boots, or even use them in the settings where minor differences are likely to matter. Buy the ones you think look nicer.