I'll agree with you to a point on the hit and miss comment. I think a lot more of the issue with RROD and E74 comes from user error. What it comes down to is being smart about where and how you place your console. I know it seems like it *should* be good vertically, but it's really a bad idea. Discs tend to get scratched and you're blocking a whole slew of vents that expel air to help keep the console cool. A lot of people also place their console inside enclosed spaces in their TV cabinets, meaning the hot air has nowhere to go except around the console, causing it to heat up.
If you want to avoid RROD, have your console in an open space, with little or nothing around it. Also, lay it horizontally. I've had a 360 for about two years with no issues whatsoever. Some of the issues are system defects and such, but I firmly believe many of the issues are simple user error. These new consoles are not like the older consoles where you didn't really have to waorry about overheating and air vents - these are consoles that use a lot of power to create the HD performance we know and love. You have to treat it right if you want it to last.
JB
2011-2012 Microsoft MVP for Xbox!