About time I posted something on a TSC forum, but like whatever.
If you just would like to fill the charts and get a high rank in Advance games, pick any one of them, they are all great. Remember though, Advance 2 scores will take a lot of your time (if you want to get a decent rank of course) and you won't enjoy it at all. Either way, choose whatever you like.
If you're going to try beating time records, then you'll have to try your best. I'm currently trying to improve some of my Advance 2 times (and I sincerely hope that Combo will come back one day and try to get back his 0p leadership which he cares about a lot). Also, I always care for my own Advance 1 time leadership (ring/score charts too), so I'm ready to defend it at any time someone decides to take it.
Long story short: if you want competition, go and play either 1st or 2nd.
Good luck and have fun in competing.