Isn't being a realist the only problem here? Do you think Brahms really meant "all in one bow"? Or did he mean "all together"? As a performer aren't you supposed to use your faculties to express what you think are the composer's intentions with an added dose of personal taste? Didn't you use the bowing you needed to present the music as conceived and interpreted and are fixating on a slur line? That is a wonderful piece of music and I'm sure the breaking of the slur line went unnoticed by all except you. Your postings here reveal you to be a knowledgeable, serious, consummate musician, so don't beat yourself up over a slur line. Would it be that all of us could rise so high. I can't answer the equipment question you posed as the only time I've played on a top drawer instrument and bow was a disaster. Such an instrument was thrust into my hands with owner saying "would you like to play it"? I looked at the diamond incrusted bow and the 250+ year old cello and was so intimidated I could hardly make a sound. I would like to relive those 15 minutes.