I've been running dual Yamaha's the past 4 years or so and have no complaints. I chose them over the Honda's for many of the same reasons you mentioned. A timing belt doesn't excite me, and being able to run the carb out is a major feature for me since I don't really use them that often and don't want to have to go digging around to drain fuel.
One other thing that hasn't been mentioned yet.. the Honda's have a fuel pump while the Yamaha's do not. That's a pro and con. On the pro side it makes running an external tank easier with a Honda, but on the con side that is just one more component that can fail. With a Yamaha, as long as gravity still applies fuel feed is a non issue.
You can run an external tank with the Yamaha's (even though most Honda owners will tell you that you can't) but they have to be gravity fed or install a fuel pump to the external tank. There are internal pump mods that can be done, but then that defeats the purpose of a gravity fed genny.
I know Champion gensets get mentioned a lot. If you only do occasional camping that might be a good option. Personally, I don't use my Yamaha's often, but when I need them I NEED them and don't want to have to futz around to get em going. I also full time so I don't really want to sit around one place waiting for a repair. Reliability trumps price for me and I know that 10-15 years down the road, my Yamaha's will still be ticking along. In the event that a repair is needed, in-stock parts and repair centers for either the Honda or Yamaha are plentiful and most of the day to day maintenance parts can generally be bought off the shelf. Champion, service centers are pretty few and far between. The Honda/Yamaha's are also just marginally more fuel efficient.
Bottom line.. either Honda or Yamaha... I don't think you would be disappointed with either one.
With Champions... I kind of look at them a lot like batteries. Box store 6v GC's will certainly get the job done, but if you want maximum performance, reliability, with the longest life cycles.. you get a Trojan (or similar). A Champion will certainly save money, will get the job done... you get the picture.
Just my own take on it.