I haven't been on GPP much as I didn't like it, but when I was there, every server except the NA unlagged server was empty. Therefore, I'd say it's fairly safe to use 1.1 as representative for Tremulous players at this moment.
On Tremulous 1.1, European players generally prefer lagged gameplay over unlagged. Sure, some may play on AA, .: () :. and such servers, but generally, they (we? ><) stick to servers such as Into the Wild and wwF. I don't want to cause a debate as to which is 'better': fact is some people prefer lagged. An obvious disadvantage to it is that ping has a bigger influence on lagged, and therefore the matches are less playable internationally (or maybe intercontinentally would be better suited), but all the international playing seems to happen on US servers.
I've noticed on Unvanquished (even though I haven't got to play on a server with people on it yet) that the EU server is a bit deserted most of the time. This can probably be partially attributed to the fact that we seem to be a conservative bunch when it comes to gaming. But maybe also the absolute presence of unlagged deters some would-be players: personally I find unlagged extremely frustrating, and I know I'm definitely not alone in that. Although I doubt providing a lagged server would suddenly bring forth a surge of European players, I think it could potentially help keep them. If not - the European server seems empty anyway, though that may change later on, of course.
It might be worth a shot to set g_unlagged to 0 on the official EU server, from my pov. However, I realize that this is a pretty big request; I wanted to bring this suggestion to your attention, even if you (understandably) don't want to un-internationalize your official server. But its frequent emptiness, the fact that international matches seem to occur on US servers and the preferences of EU players in Tremulous do provide incentive to consider it, imo. :)