I've played Cygnar since I started Warmachine 4 ish years ago. Only now have I started to go off piste into Mercs with Llaelese Resistance...with Cygnar models. And now the favour is being returned with Flame in the Darkness.
So I'd stick with the boys in blue. I love lightning. I love the rush of applying Stryker2 to the face of the enemy Warcaster. (Probability says that the boxed Stryker3 in my garage will eventually come good...right? Right?!?)
When i started playing WM/H many years ago i was torn between Cryx and Trolls. Cryx because in every RPG game i always play an evil mage/necromancer character. I also liked trolls because of the character and models. I chose Cryx and played them through Mk2 till about Fe/Mar 2018.
With the change in edition i decided that i would switch faction but game the game a bit of time to bed in. I switched to Trolls and I would not go back to Cryx. Even though they are seen as a "behind the curve" faction, i love the models, the character of the faction and how they play on the tabletop. Deffo "my faction" from now on.
As much as I LOVE dwarves, and I do love dwarves! I would probably go Convergence. There's just something about being able to own the ENTIRE faction that is just nice. Sure I don't get updated very often, but dwarves have to share their updates with like 5 other subfactions and wouldn't be considered for an update if they fell behind as long as one or two of the other subfactions was still playable. Also Iron Mother... she's quickly become my home girl, and she's just GORGEOUS! Oh and Forums/ talk about the factions. Most the time when you say "I play pure dwarves" you catch a lot of flack, but if I say, "Ya I play convergence" people are like "cool". Oh and list building? People are more willing to try new jank out because it's a limited faction, so new answers or thoughts are always welcome, as opposed to mercs, where usually the answer is "but why not play X as it's better".
Cygnar was my first faction back in 2006, love the gunmage and trencher looks. And from time to time I do play my Gator bois ( got to rep the hometown swamp in my heart) but in the end I always comeback to the boys in blue.