Looking for experience / advice on use of DimDim, GoToMeeting/Webinar, and similar.

We have had simular success and failure.  We are a global  non profit health system infrastructure company who works with a great many sub saharan african countries.  We have used a wide variety of programs to do web and video conferencing in low bandwidth high latency areas with limited success.   Quality always suffers because you just can't magic up some bandwidth for them to use.  Skype does work in most contries (some like ethiopia block it at the country level) but we usually only use it for voice because connections there drop too much to worry about video as well but we have done video over skype with some success depending on the country and stability of their internet (we use alot of line of sight RF based connections in these countries so internet can cut out alot for brief moments)  
For actual desktop sharing and more webinar based things we have used Lotus Unyte, Eluminate, Adobe Connect, webex, Gotomeeting and some others i'm sure i'm forgetting.

1. Lotus Unyte..  we started using because it was a direct plugin to skype which we use alot for audio and it was simple for our users to instal and use and connect.  after IBM bought them they are no longer supported the skype plugin feature  and we started moving away from it.   It is still easy to use but does not integrate voice connections as easily  so you are constantly maintaining two programs.  It is also very latency dependant for desktop sharing  and more bandwidth intensive then some other solutions.  Some area's  Powerpoint slide changes would take up to 5 min to switch on some users screens if they were in a high latency area others would be 5-10 seconds.

2. Eluminate.   Highly integrated voice, video, desktop sharing, Browser sharing, Preloaded powerpoint presentations with quality scaling.  Extremely complex interface.  It is really more suited to classroom style presentations or Elearning.  Do not try to project on to a big screen  its too busy and distracting with how they do their interface. But it is extremely low bandwidth for most things and with their nice powerpoint integration you upload the presentation to their server and it downsamples it based on the slowest connection present and pushes it to everyone at the same time at the same quality and is really nice for keeping everyone on the same slide with no lag.  It does have handy features for raising hands to ask questions.  It does do multipoint video (bandwidth dependant and maxes out at 6 video streams i think)

3.  Adobe Connect.   It is just awesome.  Hands down the best interface, bandwidth requirements, features, integrated audio, worked everywhere we tried it.  The problem with it is the damn cost. was nearly 20k per year and our non profit just couldn't justify the cost so we have only used it with partners who already have it set up

4. webex.  is what we use most often currently.  its cheap.  supports both voip and dail in voice.  does desktop sharing. Low bandwith (tho latency can still be an issue)  no direct video support however

5. Goto meeting.  good alternative to webex (i actually prefer it to webex but my lone voice wasn't big enough to convince the others who prefer webex they are nearly identical in capabilities)

6.  Deadicated system (pollycom)   We have now purchased IP based polycom systems for some areas.  They offer outstanding video quality and audio quality in high bandwidth areas and application sharing.  their main detractors are cost.  we paid 15+k   per location for them (was essential for dealing with some govermental agencies)  and they do not work very well in low bandwidth intermittent connection locations.

Hope this helps

--Wildstar