To audio people: LMMS, Ardour3 or QTractor?

Which one do you think is better?
I'd say that LMMS is lower on my list because it doesn't have curve-based automation (I loved that in FL studio as well as in Blender), more advanced sampler, a keyboard controller, etc. - but which one really is better?

I never used Qtractor or Ardour 3 with synths but I prefer LMMS for any musical synthesis. Especially embeded ZynAddSubFX makes it super-powerfull.

It doesn't yet have vector-based automation but it's not something I'd drop the program for. Automation system it has now is pretty usable if you give it a try. In demands some learning, but works.

I don't think Ardour 3 is going to be better than LMMS for music synthesis. When it comes out as a stable release, I'm gonna check how it works, but right now LMMS is best for me.

Especially embeded ZynAddSubFX makes it super-powerfull.

This makes LMMS the best choice. Your most versatile synth, even against most commercial offerings is ZynAddSubFX. I've used both the VST, and native LMMS compiled version. The VST is almost 75% slower. Yes, slower. That means you have to cut the number of voices in 1/4 to play the same chord in realtime. If that doesn't seem like an issue, keep in mind that Zyn has 8 separate 50-voice unison oscillators which can perform PM, FM, RM, or Morphing independently of the other 7 oscillators. The waveforms used are built on 128 additive harmonic synthesis engine. There are about 20 base waveforms to add harmonics to. So, to sum it up, use LMMS. The synth power far outweighs the automation downside.

But what if LV2 makes the differences negligible? (Though IDK if they're working on that port).

But what if LV2 makes the differences negligible? (Though IDK if they're working on that port).

I don't think there will ever be a LV2 port, as LADSPA(precursor) is a GUI-less method of plugin creation. Zynaddsubfx relies very heavily on it's GUI(additive synthesis, EQ, Formant Filters, custom drawn resonance curves, etc.). Even with the GUI, it would take a complete conversion of the engine code to make it an LV2 plugin.