I've met a number of Downers, and the greetings are different depending on how well I knew them previously. It is like meeting a stranger whom you know on one level, but not on others. Fortunately, I knew all of them from photos, so recognizing them wasn't a problem. Those whom I knew well from chatting or e-mailing usually ended up getting a hug.
My first meeting with
Guinevere was unexpected and curious - we had arranged to meet in London at the place we were staying, so I was walking there with my luggage dragging behind me. I saw someone heading in the same direction and looked more closely, thinking it just could be her. Then I approached her, she looked at me, and we met right on the sidewalk of a London street! The trickiest part about greeting her was figuring out that the convention in countries with a strongly French influence requires a triple kiss on the cheek (or the air right next to the cheek). I was a bit confused trying to remember if it's right-left-right or the other way around. We both survived and look forward to further opportunities to get together again.
I'm always sorry when circumstances are against a meeting, as recently, when
Lommy and
Agan were near to my home, but I didn't manage to meet them. Why is it that our families think they need our time and attention?!
As to the number of Downers met - yes, it does depend on where you live. A closely populated area or continent gives you a better chance. Another factor is how travel-happy the respective member is, and whether those trips are planned to include opportunities for meeting. (That also involves how expensive travelling is and how much free time one can allot to it.) The third factor is a possible membership in a Tolkien Society and/or attending functions where other Tolkienites can be seen. I highly recommend that - a great way to connect online and real life fandom!
I haven't yet met a Downer at the German Tolkien Society meetings, though some have heard of the site, but Oxonmoot is a great opportunity - and we've managed to get some people there interested who later joined up!