ORIGINAL: biam
I'm with John on fuel valves amd power panels also, not needed! Two line or fuel dots and tees, thats what I use. One of the first things I tell newbies is not to go crazy buying everything they think they need. Do a lot of research instead, and talk to the guys at the local club and see what is being used,(and what isnt)!
I think all of us that have been in the hobby for any length of time have all tried the fueling valve though. When they work they are great. Once you have one stick it will be the last time you use one. In my case it stuck with the fueling tip installed. It stuck so well even when I got it home I couldn't get the tip out. Sense that time I have seen countless of them stick opened and the tank couldn't get pressurized. I ended up doing the split line like John uses that day at the field but I had to pull the cowl off to get at the lines. I know others that clean, oil and replace the O-ring in the valve on a regular basis and love them. Just too much work for me when there are easier systems to use.
The split line is about as easy as they get!