The main 2 DAWs I have experience with are Sonar & Samplitude. And it takes about 4x as long to encode an MP3 in Sonar / CW as Samplitude. Interested if anyone knows why?
In the past week I've done about two dozen renders in reaper and samplitude. Reaper definitely has an edge in rendering speed. Both wave and MP3.
I use both daws pretty regularly at the moment. They both have some really great aspects.
Most of my final mastering is done in samplitude. And recently, I've also found myself using it more for day to day voiceover work and small mixing projects.
All mp3 encoding algos are not created equal. Some DAWs / wave editors don't go into great detail letting you know exactly what algo is being used but will at least let you choose faster / lesser quality or slower / higher quality.
I always choose the slowest to hopefully get the best quality. It's not all about the bit rate.