Adobe Connect Meetings are intended to support up to 100 concurrent attendees (you count as one, so think of it as you and 99 others), while the Seminar or Webinar rooms are able to handle 200-1500 concurrent attendees.
Is it a good choice? Many people think so, and I have had good success over the years of reaching groups large and small with Connect. Most of the time, it is done with little to no issue, as all that is required is that the attendee has a reasonably current version of FlashPlayer and Internet access. Many times it comes down to personal preference of the tool available, and functions/workflows within that tool. I may be a bit bias, but I would say it is a good tool.