Hi there
Well I am not playing, but from my friends from GW1 tell me; there are updating the game more atm (hence why there is more gw1 players on at the moment).
Make of that what you will.
As for my opinion (which is most probably biased towards GW1); I've played both games. GW2 has a lot of instances and is an open world as you already know, where is GW1 is instance based. Even with a lot of funding for the servers, this means that GW2 might have lag issues for you. I am not a huge fan of the combat system, but I know they put effort in upgrading it however recently they did some changes with the talent tree thing I believe it is, and it really pissed off a lot of the current community.
My biggest issue with GW2 beyond the whole jewel stuff, is that for the most part a lot of people are just doing grinds and trying to buy legendary items.. this is just a carrot and stick method. Do this if you are interested in just getting the next best item, after the next. GW2 *does* allow for way more than that, but because a lot of the community is so geared towards it, the game will try to shape around that very dynamic.
so to summarize it.
1. If you are interested in getting legendaries like Twilight, you like open world, if WvW was one of the best pvp experiences for you, you like doing those random battle events that happen maps; play this game its definitely going to head in these directions
2. If you like instance based (which gw2 has but I mean more like a CORPG), then come reach GW1 at embark reach ad1.