Honestly you can get good sounds from any modeler. Many of the stock IRs are not good, though. So that takes more money to get going. $10 here $20 there starts to add up. Fractal is different. You can buy third party IRs all day, but the ones it comes with are really good already. I feel like it gets a good tone pretty much out the gate.
Stick to the authentic tab if you want to keep it simple. It has the same arrangement of knobs just like the amp has. If you like to tinker, there are sooo many settings that you can get whatever sound your heart desires. I sold my Bogner XTC 101b and 4x12 basket weave with greenbacks to get the turbo, fc-12, a few exp pedals, and a cheap frfr just for sustain. I couldn’t be happier. Every gig I am getting compliments from all these different bands I fill in or play on the regular with and sound crews. The tones are great, the stage volume is more controlled, and the tweak ability is unrivaled.
When you start getting into the modifiers it is jaw dropping. Look on YouTube for Simeon Harris or Leon Todd. They have many videos that go from simple to melt your brain with inspiring tips and tricks. There are of course many others, but those two really opened my eyes to some wild possibilities. You’ll want to read all the manuals, and go through this forum. There are tons of really helpful posts. You won’t realize what some of it is about until you get into it. Then you’ll wonder how you ever lived without whatever it is. Haha