I'm sending my first completely home studio tracks into be professionally mastered this week, and I found discovered the most frustrating discovery: the rendered out tracks sound a great deal better than the original playback of the songs within Nuendo. Suddenly, dozens of mistakes and level problems are jumping out at me. (I even found studio dialog hidden in the back of the mix, that I couldn't hear when I went back to the song without soloing the track). I've called the mastering house, telling them not to use the tracks I left them, and am having to go back and remix all the tracks in my project. On the surface, you'ld think that this was a boon. However, to me, it feels like you can't accurately monitor while you are writing and mixing. I make relatively complex music, with lots of layers and textures. If I hide something in the back, I don't want it popping to the front after I've rendered out. Damn it! It takes about real-time to render out the tracks, so for every time I render out and the listen, I'm pretty much tripling the amount of time it takes to get stuff done. Add in the 'vocal one up/one down' process, and you've got 6 times as much work during render, per track - that's like two days, after all the main mixing is done, rendering and fixing mistakes, just to get the files ready for mastering. Also, it means that Nuendo's 'online' rendering, (where you are able to place analog gear on various tracks during render/mixdown) is a crock. The tracks sound so much better after offline rendering, that there's no way I can compare them to the original sound. So, beware. I would be shocked and amazed if this issue wasn't present in every DAW system, to varying degrees - it's obviously a performance tradeoff of some kind.