https://www.reaper.fm/index.php
I have a license for Reaper and its what I use most of the time. I find it a reason to stay in raspberry Pi. To me its as deep as i need it to go. It hosts most plugins I have installed, allowing me the most complete exposure to whats available to me in linux. Every parameter is exposed to reapers modulation capabilities. And if not, there are many ways to create or receive modulation through a DC coupled interface like my favorite so far, the expert sleepers ES-8 or ES-9, with optional ES-3 and ES-6 expanders,
Reaper is plugin delay compensated and does sound very tight to my ears when i use it as the brain of my mixed studio. I have a variety of gear including midi desktop, midi rack mount, usb midi, external sequencers for midi, hardware midi controllers, ESI M8Uex, a modular synth that includes the regular stuff besides my unit and ES-8, ES-3 and ES-6. and some ipads etc. So far I have been able to integrate them all from midi control to Reapers amazing routing capabilities and can end up passing modulation to something like Cardinal to effect a change that it will send out of the ES-8 to supply cv modulation to my hardware filter or oscillator. This can get very expressive because the modulation you can develop in Cardinal is intense and can be mixed with other modulation before it is output. keep all your modulation in a single interface outputting up to 8 separate streams of CV or audio per plugin instance. I find it to be enough honestly.
Reaper is only $75 for a license. I feel it is worth it for such a deeply usable interface that is in active development and is constantly being refined. The level of support for reaper is intense too, so most questions are covered on various youtube vids and if not, the facebook groups have a hundred people waiting to answer any questions. I have found them to be very helpful.
One big feature that keeps me using and loving Reaper is the MegaBaby midi sequencer. This sequencer makes using Reaper feel like using hardware, with immediate control over pattern, transpose, automation, all mapped to a hardware controller of your choice. its output can be midi which you would then record to a track. You can also record the audio output of whatever sound source you are using to a track. You might open a slew of samples in their own player and set them to respond to any note triggered sent by MegaBaby. You can very quickly make a setup with layers and tracks that can be controlled at a very high level, basically making a sweet spot between step writing and tactile control over whats playing while still allowing any interaction desired for a performance or composition environment. Best of all is just jam while you record, stay in midi before going to audio so the files stay small and edit down to what you like with no sweat.
to be continued!
instructions for updating reaper