Craving some gapless goodness I decided to try 1.1.4 with gstreamer. Previously I was using 1.0.2 with mplayer and didn't even have gstreamer installed on my system. After installing gstreamer and flac, mp3 and ogg support (tested to work with aplay and gst-launch) I started 1.1.4 with the gapless box checked and all is well... except it seems to randomly lose the connection to gstreamer. Sometimes its after sitting idle for a while or after one album plays through and I start another one, sometimes just randomly. The progress bar stays at zero and nothing happens when I try and start a song. Restarting gmb fixes this, as does changing to the mplayer backend instead without restarting, though switching back to gstreamer only works with restart. I'm not sure if the issue is my new gstreamer setup or with alpha gmb, but I figured I could provide useful feedback either way.
When using the gapless mode in v1.1.x, gmb uses gstreamer's playbin2 instead of playbin which as the doc says, "playbin2 is considered UNSTABLE" and "When playbin2 is stable, it will probably replace playbin".
So the bugs may be in playbin2, it is also possible there are bugs in the gstreamer bindings for perl, as they are not widely used.
So currently, I have other priorities (like finishing what is needed for a beta), I'll focus on playbin2 later if it is still causing problem then.
FWIW this behavior is the same with or without the gapless option enabled.