I used to shift front and rear at the same time too. Works well if everything is adjusted properly, but it took a lot of concentration, and was also pretty noisy. My speed hub is much more quiet in comparison. Now I shift without really thinking about it. Back six, or up three, it's pretty seamless and intuitive.
There are simply tradeoffs between derailleurs and IGH. Personally I'd take my Sram XO before any other IGH except my speed hub. Rohloffs are somewhat heavy and expensive, but for me it's been great. I bought mine without even having ever seen one before. They are imo worth the money, and highly recommended but buy new. Don't buy a used speed hub unless you know a great deal about them.