Do not get an appliance package. As has already been said, different manufacturers excel at different appliances. Also, you can save money by deciding which appliances are more important to you and those would be the ones to spend on. If for example, a fridge to you is just a box to keep things cold, then you certainly don't need a Thermador fridge, and a Whirlpool would be fine and save you thousands. I myself was "lusting" after a Subzero fridge, and ended up with a Kitchenaid, saving me about $4000, and my Kitchenaid fridge has performed flawlessly. Or perhaps you feel a DW that'll just clean the dishes is fine, and you don't need to spend thousands for one that has 14 cycles, a self-opening door (one of the Miele DW's has that) and the like. So if you are looking at budget as a reason to get an appliance package, that would be wrong thinking.

Also, the "matchy-matchy" appliance look is considered dated.

Also, you raise your "appliance risk" by buying all one brand. If something goes wrong with more than one appliance, you'll be dealing with the same people for multiple appliances, and if you don't get satisfaction, you will be stuck with that poor customer service for all your appliances, since they're all the same brand. Instead, you should diversify--just like the stock market. You wouldn't put all your money into just one stock would you?

Final point--you may think you are getting all one brand, but many companies just buy appliances from other manufacturers, and rebadge them with their name, and then add a big upcharge. Thermador and Dacor do that on several machines they sell. Some of the Thermador DW's are the same as the Bosch's since they're owned by the same company, BSH. Viking fridges are made by Amana. The Dacor MW's are made by Sharp, look identical to the Sharps except for the badge, and cost double what the Sharps cost. So, buying an appliance package doesn't mean you're actually buying appliances made by the same company. Do some research on this forum, or post here if you have specific appliances you want to know about.