I've had similar great experiences with some of these companies, too. I've also been really pleased with Purple Onion Designs and Chris from Peerless Watercolors just made a wonderful lasting impression on me recently.
I am not sure if the average company knows how much great customer service and kindness means to all of us (and how big of a turn-off the opposite kind of company leaves on us). Once in awhile I drop a note to companies when I am really impressed. I think we all need to do that more often so the nice companies realize we appreciate them
Of course spending money on their products sends the same message.