During the backingvocals, I allways dub them. Sometimes I dub the lead, but thats not so commom in my productions. I realy like that the lead stand out without dubbing. I use compression during tracking, about 4:1, slow attack and relase.. Just to make sure that the convertor dont clip. During the mix, I can use 8:1 and faster attack and relase. I use 1176 compressor on the vocal. Sometimes the SSL bus compressor. I love the 1176!
I am not a mastring engineer, I send my mixes to people who are experts in mastering. If I do a mastering, I use a 2-1176 stereo-compressor, the ME loadness maximizer or a SSL bus compressor. I dont think steinberg have a "must have" compressor... I really like the waves SSL, API and the V-series plug-ins.