I've a hybrid configuation (soft+synth), so maybe I can help too.
I've worked with Reason, Cubase, FL, Live and PT to make beats. And from my point of view, Pro Tools is the easiest.
Sure, you must learn the soft and not only read the manual. But if you know what you want to do, it's the best tool to accomplish your work. There are tons of tutorials and help on the web.
If you want the piano roll to build your drum sequence like FL, you can use Boom or Idrum, I prefer Idrum 'cause you can import your own samples. You can use the Midi map too, or even the grid mod. A lot of choice to fit your taste.
Then , you can have Structure or Transfuser to sample/build all your beats. I prefer Structure, 'cause I've PT 10 and the Drag&Drop feature from a PT track is soooo gooood!!!!
But you can work directly in grid mod too
In the version prior to PT11, you can wrap Vst's, so you can have rtas, vst and aax( PT10) plugins running in the same session without problems.
And the must, is that you can mix your beat in the same time you're building it. I do it all the time and it such a time saver, no need to bounce track, etc...
I can use PT like only like a sound module for my MPC or like the master sequencer. No limitation at all..... I can do all in the box or use my MPC and easily bounce in PT.
I like FL, but I think if you want to save time and work directly on your beats with or without MIDI, PT it's the way to go.
About Avicii, all his beats are mixed in PT ....so even if he rocks with FL, at the end he needs PT to polish his work. Just my 2 cents.