I had my first 9th edition game yesterday. I brought Tau vs Necrons.
Farsight Enclave
2 Commanders, 2 Maker Drones each
6 Breacher Teams. 1 Guardian Drone, 1 Shield drone each
2 Riptides
3 Tactical Drone Squads of 5 Marker Drones each
5 Crisis Suits (CIB)
Some positives? I loved Farsight sept more than I thought I would. Treating anything within 12" as having 1 markerlight, and re-rolling wounds with 6", helped me more often than I expected, especially since I was trying to be mobile and I had thinks in my face frequently. This was my first time using Crisis Suits, and holy moly, cyclic ion blasters are disgusting how powerful they are. However, that was nothing compared to bringing an iridium suit with reactive countermeasures to make one suit have a 2+ save that treated all -1 and -2 AP as 0. They soaked up tons, and tons of infantry fire, and I only ever lost 1. This was my first time using Breacher Teams as well, and while I really liked being able to shoot 6 STR -2 AP 1 damage shots from infantry, they really didn't accomplish too much. My Riptides were clearing the field of big things that needed a stronger gun anyway, so my Breachers ended up shooting at infantry mostly. I really would've preferred volume of shots from standard Firewarriors. Next time, I'll have more of a mix.
Now to the negatives, or rather, thee negative. I did terrible at secondary objectives. I did fine at the primary, but I couldn't decide on any worthwhile secondaries, and even after the match, I can't figure out what I should have taken. I really hope we get more, because by the end of the 3rd round, I had 9 points total from secondary missions. I took the secondary from the mission, which I was scoring on no problem. But then I took one of them (Linebreaker, I think?) and managed it for a single turn only, and raise the banner, which I managed once. Morale wiped infantry raising the flag in one spot right before they could finish. I did succeed in another spot, but he swarmed it a turn after and cleared my flag. It was rough.