Definitely have to agree with Jeff there.  When we upgraded from the CE changes gave us a performance nightmare.  Having spent some time updating our code to work within the new CE we now have better performance or the same in most every case.  There are a few outliers where we still haven't been able to get performance back to where it was, but those areas are seldom used and not a priority.  It really was rough having to tell customers to utilize compatibility mode, or trying to justify use of a TraceFlag.