A young, newly wed employee in our office, who currently is in an apartment but who has begun to shop for a condo with her new husband, asked the middle aged among us at work "what brand of appliances do you own, what should we be looking for". I explained I buy by feature and color, but don't care if badges or name brands differ, and that in my mind the only reason to buy all appliances with the same brand is if the company is offering major discounts or rebates to customers who purchase a bundled group of appliances, and then only if the feature set and quality you want is present.
I told her in my case the DW is Bosch (14 years old, no repairs or service issues EVER), gas range is Frigidaire (one of only four non-commercial brands offering gas convection when purchased 2001; now many more choices), the over the range microwave hood is Amana (purchased because it was smaller vertically than the competitors by 2 inches, offering a few inches of extra space between it and the range cooktop), and the counter depth fridge is Frigidaire Gallery (the Kitchen Aid competition would not fit under the cabinets above the fridge; Frigidaire fit without mods) which is 11 years old, only service issue was an icemaker solenoid that failed and which I replaced myself (thank you Allan/Whirlcool for link to repairclinic.com). The laundry set, which is in the garage where "matching" is not essential, is Electrolux.
So I have a mish-mash of brands but I like the feature sets of all of them and have had only one lemon (a GE over the range microwave bought with the range and DW as a bundle---merchant gave a discount because I bought three major appliances at once, even though different brands--lost its control panel and the repair was the same as the Amana so I took the new Amana). I researched my purchases (CR, asking for input here) and bought what I wanted, but never as a set (the counter depth fridge was purchased alone, several years after the range DW and MW) and the only thing I ever regretted was the GE over the range microwave, which burned out (control panel, not the tube) after less than eight years of light use. The GE was also bulky and I was much happier with the Amana's smaller profile and no frills control panel. I never used most of the GE's fancy features.