[someoneiam]

Reaper has a plethora of built-in effects and you can script your own in JS or Python or EEL2. You'd have to use third-party synthesizers though.

That said, the GUIs of said effects are basic, but I personally still find them useful.

There is no difference between the evaluation, non-commercial and commercial tiers.

I'd say, give it a try, the days when Reaper was a niche DAW are way in the past. Especially if you like the idea of being able to customize every corner of your DAW, Reaper is the no-brainer choice.

[spacechild1]

Nitpick: the JSFX audio effects you're referring to are scripted in EEL2. Reaper itself can be scripted with Python, Lua and EEL2 (see http://reaper.fm/sdk/reascript/reascript.php). It also has a C plugin API.