Here's my contribution on the topic and some thoughts on the 1.4.0.64 version. I see you had some chatter earlier about the GUI being designer towards more "seasoned" users. I don't know if I'm "seasoned" enough, being tinkering with Linux for the past 13 years, but anyway.
The very fist time the main window appeared, my first thought was: "wow, clutter free++;". I see either my groups have disappeared or they're not yet coded in, but other than that, I can finally see the mood-messages and apparently also if the other end has a webcam (which is one feature I've been waiting VERY eagerly since m$ killed netmeeting and then the only universal enough way to use my webcam with gnomemeeting). The only thing that caught my eye on the main window was the location of the search-bar. I really wish it was at the bottom of the screen. No idea why, but it somehow feels out of place at the top and the line showing my status and credits would make a fine first line.
The next thing I tried was a call to the echo123. The call however didn't even start, I only got a window telling me "Call failed: problem with audio playback", while the console was flooded with "ALSA lib pcm.c:2014:(snd_pcm_open_conf) Invalid type for PCM phoneline definition (id: phoneline, value: cards.pcm.phoneline)"-messages. The machine has 2 ALSA-compatible audio devices; first being the SB Live 1024 which I use for audio output, and Logitech Quickcam Messenger, which serves as a microphone; Both devices work with other programs just fine.
Now being able to call, I tried chat. I fired up a contact on the other side of the planet and said hello. To my surprise, the message didn't appear in the chat area after I hit enter key. Did it stall? Did my line just go down? Nope, after 10-15 seconds my line appeared with the answer from the chat buddy. After that the conversation was seemingly real-time and I had no other problem with delays. For some reason I was unable to select any other layout than "skype" in the settings. The outcome however looked a lot like the "IRC"-option in the older Skype, with the exception that all the line colors were the same, making the conversation somewhat hard to follow.
One of the more annoying of the small annoyances was that the text entry field in chat window isn't focused when the window is focused. So if for some reason the text box wasn't active when the window was unfocused, I can't alt-tab into the window and then start typing.
Talking about the chat, I see there's a "show others when I am typing" feature in the configs. I was talking with another client who was also trying out the 1.4, but we didn't figure out how the fact that the other is typing is indicated at the other end, or if it was yet unimplemented. Grouping all the conversations and offering the 1 day, 1 week, 2 weeks and so on options is IMO a good idea. One area of the chat that could use improvement comes in mind. How about making it work in two modes. The first mode would be one-on-one chat, where the "call", "send file" etc. buttons would be in the divider between chat/entry boxes and the participant list would be automatically absent. Then when more folks join in, the userlist would appear.
I also tried transferring files, which went without any hickups. The file transfer window was a real improvement since the earlier versions, which had several oversized windows for multiple transfers. This Firefox-ripoff is just fine. One oddity was the "Finishing in"-status, which seemed to tell how long the transfer is going to take, but not how long time is still remaining. When there are lots (5 or more) transfers and a new one is added, the new one overlaps the old ones. See the attached file.
I liked the new profile edit window. I found the date entry pretty intuitive when compared to the older versions. I also accidentally scrolled the 'gender' dropbox and found the 'unspecified' option. It made me wonder, if a "I don't know, help?"-option would be in order with a help text like ("put your hand in your pants, feel around") and a normal wizard-type dialogs to assist with that

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During the day I also kept an eye for the notification area icon. Atleast for incoming chats, maybe the default action for clicking the icon could be opening the chat window instead of the main window. The icon itself seems to be rather large (taking about the space of 2 normal icons), but only the green part is clickable, which made me do several "miss clicks" on it. When the flag is displayed, the area to click is even smaller as the grey area under the flag doesn't seem to count. Also, the background of the icon seems opaque.
Anyway, not counting the non-working voice calls, everything else seems to work. I'm looking forward for more alphas or betas.