Just had some fun with REAPER 0.43 and I must say it's great. Add:
1. Plugin Delay Compensation for VST plugins (essential!)
2. Send tracks (unless they're already there and I only haven't found them
)
3. Flexible routing so that side-chaining can be done.
4. Time-stretching (
DIRAC based preferably)
...and REAPER will become my dream-come-true multitrack!
Keep up the great work and I'll keep on beta testing (so far I've only found the VST subdir problem, but that's already been mentioned).