I use(d) Sonar, Cubasis, Reason, Ableton Live and recently bought Reaper after having tried it.
It is a huge surprise. I still use Ableton Live notably for Max for Live extensions but I was fed up by the weight and CPU ressources and the weak evolution of it comparing to its price. Notably MassiveX and Live or Maschine and Live on my MacBook Pro Core i5 RAM 8Go is very bad: CPU ressources are too high and the computer becomes too much warm.
With Reaper I can use all of this soft synths without any problem, the CPU stays normal. I only had troubles with Waves AR chamber.
The workflow of Reaper -after a little adaptation- is very nice and flexible. The sound is perfect, the design very nice to use and it never crashes either on my PC desktop and on my MacBook. The relation price-quality is just incredible with constant improvements.
I'm still discovering functionalities reading the good and complete manual and seeing the excellent videos.
The power of this software comparing to its weight and ressources consomption is just amazing! And the ability to melt Live with Reaper (Rearoute on PC, Soundflower on Mac, IAC on Mac for midi) allows to use the best of each environnement.
Not an easy one but a true creative masterpiece for sure.
The water seems cold at first impression. I'm not a fan of the GUI but the manual is complete and the more you dive in this instrument (to call it an effect would reduce it too much) the more you love it.
Hours and hours of discovering and ears pleasure, very inspiring too.