I’ve used them somewhat. The schematic capture works pretty well. The board layout tool is pretty decent as well. Even the autorouter works surprisingly well. The biggest drawback I had was the lack of component footprints. Creating your own footprints is a very tedious and time consuming task compared to Eagle. However, it is free and doesn’t have the 2 layer or dimension limits that Eagle PCB has.
You might want to check out Kicad. It’s another open source PCB tool. I haven’t used it at all.
I’ve used the gEDA pcb a fair amount (come to think of it, since before it was absorbed into gEDA). Its interface is clumsy here and there, and it’s definitely a pain to make components properly, but it works perfectly well. It’s also under reasonably active development, so it is getting gradually better.
I’ve been meaning to check out kicad as well but haven’t gotten around to it.
When I first started out with gEDA, I was frustrated at the amount of effort it took to create a layout from a schematic. When I tried KiCad, I was extremely pleased at the relative ease in creating a layout, but I absolutely abhorred the key assignments, so I went back to using gEDA just for it’s awesome (to me) schematic editor.
It should be noted that creating or modifying a layout in gEDA from a schematic really isn’t all that hard, it’s just that it seemed odd that there wasn’t just a button to press or something along those lines.