I'm taking it for a spin and sharing my notes as I go:

    * UI has pleasant colors, I could get used to comfort of having all relevant info in side panes
    * The gdb starts in /opt/gdbfrontend directory, would be nice if it changed to dir you executed gdbfrontent in
    * I wish I could collapse Disassembly list - I don't want to see it ever
    * Icons don't have tooltips and some are not so clear
    * "Sources" pane doesn't actually have all the sources, some appear only after I set breakpoint in previously missing file
    * Breakpoints set manually through GDB console don't show up in UI breakpoint list
    * Usual shortcuts F10, F11... for stepping over and into don't work, while gdb commands n and s work only if lower pane has focus, so interface requires more mouse clicking
    * In my specific case it doesn't detect local variables or respond to added watches (fields to right stay blank)

This is where I stopped using it, don't have time to debug the debugger. I appreciate the effort and it looks like it might be extremely handy tool in future.