The international aspect of this is a big driver. We need something our 2nd world customer can use simply and reliably. The integrated VOIP is a must; dial in is not reliable on their end and there is already enough language barrier with their accents that the delays in the teleconference system we use would make it unbearable for both sides.
I think if they're horribly bandwidth limited the real problem will be the video. Most of these will gracefully degrade video to keep audio as packet loss climbs, but a few merge the two into a single stream and that gets really annoying fast if working with a bandwidth constrained site.
Some do some pre-buffering if you're using a slide deck before the next slide is needed -- the presentation based ones for huge conferences (WebEx) do this instead of relying on the screen share catching up.
In general it's best to test with the site known to be difficult before relying on any of them for a really important meeting. Just have the folks at the far end assign someone to do an hour of tests and try a few products during that timeframe. Then do exactly the sort of usage that will happen during the real deal.
When I supported video conferencing stuff, we always had at least one customer call a quarter or so who'd say "it works fine when we test but falls apart when 30 people are on"... well yeah, of course... how big is your internet connection? Perhaps you need an MCU on-site to gather all the locals and then link that MCU to the conference MCU? ;-)
Audio only was always the "lingua franca" of conferencing. It always worked. Slides, video and remote control, were the next levels up from that, and the products would usually fail in that order in reverse when bandwidth or packet loss rates sucked.
My favorite was the people who called who were doing HD quality video between multiple vendors so it had to use high bandwidth and not very compressed. They said their conferences in the morning sucked. And only sometimes.
We looked and saw their bandwidth was really high for a typical HD call on the main conference room endpoint. So we set up a test call to us at the usual time of day of the call, etc. They called right before the morning meeting.
"Hey that looks pretty good, but yeah... I see it freezing. Can you close the blinds behind you?"
"Sure. Why?"
"The wind is blowing. Every leaf on that tree and all the branches are moving. That's driving the need to update more blocks of the screen sky high. Yep. There you go. Half the bandwidth and boy that looks better!"
LOL. Tech. Always entertaining.
That one had gotten so political the bosses wanted an update. I walked into my boss' office who had a sense of humor...
"Company X's problem with the conference room is fixed. I told them to cut down the tree outside. Or close the blinds."
He knew exactly what had happened and started laughing.
