The strengths of the old curriculum were the concepts you learned through 6.001 and using Scheme, not the Scheme skills themselves. Do I think 6.034 would be significantly different if I had to use Python versus Scheme? Not at all - and frankly using Scheme added nothing to my experience in that class.
I had a different experience in 6.034 than you did, I suppose. I think Scheme suited the class well and offered a nice way to express searches, minimizations, and decision systems. I'm sure you can do everything you can do in Scheme in Python but you could also do it in Java. Functional languages are particularly well-suited to these tasks. I wouldn't necessarily pick Scheme, though. Why not use the most appropriate tool for the job? If students have to learn a new language, OK. If you really do think Python is the best tool, OK.